Calton C. Green, et al., and Liston King, et al. (the taxpayers),1 owners of real property in the Lebanon R-III and Morgan County R-II School Districts, brought suit to challenge the operating levies of the school districts (the schools) for the years 1994, 1995, 1996, 1997, and 1998. The taxpayers contend that the schools erroneously determined the highest rate of tax they could levy without additional voter approval, resulting in a tax rate for each of the years at issue that violated provisions of section 137.073, RSMoi2 and article X, section 22(a) of the Missouri Constitution. The taxpayers asked the court to declare the schools’ levies unlawful, requested in-junctive relief requiring the schools to return excessive funds, and sought damages. The taxpayers named as additional defendants various county officials within each school district and certain members of the two school boards in their individual capacities. The circuit court dismissed the individually named school board members. The circuit court entered summary judgments in favor of the schools and, in the alternative, sustained the schools’ motions to dismiss for failure to state a claim. The judgments are affirmed in part and reversed in part and the causes remanded. The appeals are consolidated because of common issues of law and fact.
As a preliminary matter, certain explanations are helpful with respect to the opinion in general. To the extent that there exist methods of calculating more than one tax rate “ceiling” or “lid,” this Comet uses the term “highest lawful levy” to describe that rate above which a school district may not levy, taking into account all relevant ceilings or lids under Missouri law. A tax levy is an amount owed for each $100.00 of assessed property valuation. The state auditor is charged with verifying that a school district’s highest lawful levy for each year complies with section 137.073, RSMo. See section 137.073.6, RSMo. The state auditor developed a set of forms for the benefit of school districts to determine the highest lawful levy in a manner purportedly consistent with both section 137.073, RSMo, and article X, section 22. See 15 CSR 40-3.100.3 The Missouri State Board of Education publishes its own separate listing of maximum levy amounts for each year in the annual Report of the Public Schools of Missouri. See section 161.092(10), RSMo.
The remaining facts relevant to this case are derived from the pleadings, The taxpayers’ petitions rely upon the state auditor’s results. The taxpayers allege that the highest lawful levy for the Lebanon R~ III School District should have been: $2.16 in 1994, $2.19 in 1995, $2.20 in 1996, $1.98 in 1997, and $1.99 in 1998. In those years, the taxpayers claim the Lebanon R-III School District exceeded the established limits by imposing the following levies: $2.75 in 1994, 1995, and 1996; $2.61 in 1997; and $2.62 in 1998. Similarly, the taxpayers allege that the highest lawful *281levy for the Morgan County R-II School District should have been: $2.13 in 1994, $2.19 in 1995, $2.17 in 1996, $2.02 in 1997, and $2.04 in 1998. In those years, the taxpayers allege that the Morgan County R-II School District exceeded the established limits by imposing the following levies: $2.75 in 1994, 1995, and 1996; and $2.55 in 1997 and 1998.4 The schools assert, using the state board’s amounts, that the highest lawful levy for all of the relevant years was $3.59 for the Lebanon R-III School District and $3.15 for the Morgan County R-II School District.
At issue in the taxpayers’ first point on appeal is the method for determining the highest lawful levy that a school board may approve, taking into account the terms “maximum authorized current levy,” as used in article X, section 22(a) of the Missouri Constitution, and “tax rate ceiling,” as used in section 137.073.1(3), RSMo.5
Article X, section 22(a) of the Missouri Constitution, a portion of the constitution commonly referred to as the “Hancock Amendment,” provides:
(a) Counties and other political subdivisions are hereby prohibited from levying any tax, license or fees, not authorized by law, charter or self-enforcing provisions of the constitution when this section is adopted or from increasing the current levy of an existing tax, license or fees, above that current levy authorized by law or charter when this section is adopted without the approval of the required majority of the qualified voters of that county or other political subdivision voting thereon. If the definition of the base of an existing tax, license or fees, is broadened, the maximum authorized current levy of taxation on the new base in each county or other political subdivision shall be reduced to yield the same estimated gross revenue as on the prior base. If the assessed valuation of property as finally equalized, excluding the value of new construction and improvements, increases by a larger percentage than the increase in the general price level from the previous year, the maximum authorized current levy applied thereto in each county or other political subdivision shall be reduced to yield the same gross revenue from existing property, adjusted for changes in the general price level, as could have been collected at the existing authorized levy on the prior assessed value.
Only the last sentence of article X, section 22(a) is at issue in this case. It requires annual adjustments to the “maximum authorized current levy” under certain circumstances, taking into account the finally equalized assessed valuation of property, the value of new construction and improvements, and the increase in the general price level. The maximum authorized current levy under article X, section 22(a) is the higher of the amount in effect at the time that section was adopted, November 4,1980, or the highest amount approved by the voters since that date.
The schools, being the movants, bear the burden of establishing a right to summary judgment. ITT Commercial Fin. Corp. v. Mid-America Marine Supply Corp., 854 S.W.2d 371, 376 (Mo. banc 1993).6 In response to the taxpayers’ arti-*282ele X, section 22 claim, the schools, in their motions for summary judgment, merely contended that the maximum authorized current levy for the years in question, unadjusted from year to year, was $3.59 for the Lebanon R-III School District, the rate in effect in that district on November 4, 1980, and $3.15 for the Morgan County R-II School District, a rate approved by the voters in that district in 1983. To obtain summary judgment against the taxpayers as to their article X, section 22(a) claims, however, the schools had the burden to establish that they were not required to make annual adjustments to the maximum authorized current levy under article X, section 22.7 The schools failed to establish that annual adjustments were not required. As a consequence, they did not meet their burden to show that the maximum authorized current levy they alleged was correct under article X, section 22.
The other of the taxpayers’ claims invokes section 137.073, RSMo. Section 137.037.1(3), RSMo 1994, provided that:
(3) “Tax rate ceiling,” a tax rate as revised by the taxing authority to comply with the provisions of this section or when a court has determined the tax rate; except that, other provisions of law to the contrary notwithstanding, a school district may levy the operating levy for school purposes required for the current year under subsection 2 of section 163.021, RSMo [requiring an operating levy of $2.75 in order to obtain state aid beyond certain minimum amounts], if such tax rate does not exceed the highest tax rate in effect subsequent to the 1980 tax year. This is the maximum tax rate that may be levied, unless a higher tax rate ceiling is approved by voters of the political subdivision as provided in this section.
The section 137.073, RSMo, tax rate ceiling applies, therefore, to all political subdivisions but contains an option for school districts:
other provisions of law to the contrary notwithstanding, a school district may levy the operating levy for school purposes required for the current year under subsection 2 of section 163.021, RSMo, if such tax rate does not exceed the highest tax rate in effect subsequent to-the 1980 tax year.
The amount “required” for 1994 under section 163.021, RSMo 1994, was $2.75. The “highest tax rate in effect subsequent to the 1980 tax year,” without any adjustments, was $3.59 in the Lebanon R-III School District and $3.15 in the Morgan County R-II School District. Applying a plain meaning reading of the option for school districts, a tax rate ceiling under section 137.073, RSMo 1994, was $2.75 in 1994. Section 137.073, RSMo 1994, did not require any annual adjustments to the $2.75 result. In fact, section 137.073.3, RSMo 1994, provided in part that, “no school district shall be required to revise *283its operating levy for school purposes below the rate required for the current year under subsection 2 of section 163.021, RSMo, if such tax rate does not exceed the highest tax rate in effect subsequent to the 1980 tax year.” See also section 187.073.4, RSMo 1994. In 1994, both the Lebanon R-III and Morgan County R-II School Districts imposed a levy of $2.75. Neither levy violated section 137.073, RSMo 1994, for the 1994 tax year.8 The same reasoning applies to the taxpayers’ section 137.073 claims for the years 1995 and 1996.
Enactment of a 1996 amendment alters the analysis. With that amendment, the option in section 137.073.1(3) provides:
other provisions of law to the contrary notwithstanding, a school district may levy the operating levy for school purposes required for the current year under subsection 2 of section 163.021, RSMo, less all adjustments required pursuant to article X, section 22 of the Missouri Constitution, if such tax rate does not exceed the highest tax rate in effect subsequent to the 1980 tax year.
Section 137.073.1(3), RSMo Supp.1996. (emphasis added). The revised statutory option specifies that, beginning in the 1997 tax year,9 the schools must adjust the $2.75 levy “required” under section 163.021.2, according to the provisions of article X, section 22(a) of the Missouri Constitution. See sections 137.073.1(3), 163.021.2, RSMo Supp.1996. Similarly, section 137.073.3, RSMo Supp.1996, no longer stated that school districts shall not be required to revise their operating levies below the “required” amount listed in section 163.021.2, RSMo. See also section 137.073.4, RSMo Supp.1996.
In view of the 1996 amendments, therefore, the schools had the burden on their summary judgment motions to establish that they were not required to adjust the tax rate ceiling. The schools did not do so for the years 1997 and 1998. The schools, therefore, did not meet their burden on the taxpayers’ claims based on section 137.073, RSMo Supp.1996, for the years 1997 and 1998.
Because in these summary judgment proceedings the burden is on the schools to show as a matter of law that they were entitled to summary judgment, the judgments must be reversed in part and the causes remanded. This is because the schools failed to prove that annual adjustments to the maximum authorized current levy were not required under article X, section 22(a) for the years 1994,1995, 1996, 1997, and 1998, and because the schools failed to prove that annual adjustments were not required to the tax rate ceiling under section 137.073, RSMo, for the years 1997 and 1998.
The schools contend that the taxpayers cannot obtain refunds under section 137.073, RSMo, for two reasons not related to the merits, neither of which the trial court reached. First, the schools contend that, in order to obtain refunds under section 137.073, RSMo, the taxpayers should have filed suit in each of the years in question in the period after the schools assessed levies (in July or August of each year) but before the levies became due (on December 31 of each year). Second, the schools contend that the taxpayers are not entitled to refunds under section 137.073, RSMo, because the taxpayers did not pay their taxes under protest in the years in question; as described in section 139.031, RSMo. On remand, the trial court may determine whether refunds are permitted as a matter of law for each of the years in *284question and whether requests for refunds were properly and timely asserted.
Finally, the schools contend that the taxpayers are not entitled to a refund for the 1998 tax year under either article X, section 22(a) or section 137.073, RSMo, because Constitutional Amendment Number 2 permits the levies in these cases. The amendment modified article X, section 11(b), which now reads,
Any tax imposed upon such property ... shall not exceed the following annual rates [without a vote, as specified in article X, section 11(c) ]: ... For school districts formed of cities and towns, including the school district of the city of St. Louis - two dollars and seventy-five cents on the hundred dollars assessed valuation.
Section 11(b) addresses the amount of tax that a political subdivision may levy without voter approval. See Three Rivers Junior College Dist. v. Statler, 421 S.W.2d 235, 238-39 (Mo. banc 1967).
The amendment does not apply. School districts set the levies for 1998 not later than September 1, 1998. See sections 164.011.2, 67.110.1, RSMo. The voters did not adopt the amendment, however, until November 3, 1998, and the amendment did not become effective until December 3, 1998. Mo. Const. Art. XII, section 2(b). The schools set the 1998 levies and the levies became official, therefore, before the effective date of the amendment. If the school district imposed an unlawful levy for 1998, the later constitutional amendment did not ratify the earlier unlawful tax rate.
The schools contend that the amendment does apply because the taxes for the 1998 year were payable on December 31, 1998. The amendment, however, affects and concerns only the setting of the tax rate; it does not affect or concern the payment of tax. Although the taxes became payable after the effective date of the amendment, it does not serve to validate a tax rate set before the amendment took effect. See Southwestern Bell Tel. v. Mahn, 766 S.W.2d 443, 445 (Mo. banc 1989). The schools’ claim, therefore, is without merit.
In their second point relied on, the taxpayers claim that the trial court erred in dismissing the school board members from the suit.
As one basis for dismissal, the individual school board members claimed official immunity. The doctrine of official immunity recognizes that “society’s compelling interest in vigorous and effective administration of public affairs requires that the law protect those individuals who, in the face of imperfect information and limited resources, must daily exercise their best judgment in conducting the public’s business.” Kanagawa v. State ex rel. Freeman, 685 S.W.2d 831, 836 (Mo. banc 1985). Under the doctrine of official immunity, a public official is not hable to members of the public for negligence that is strictly related to the performance of discretionary duties. Green v. Denison, 738 S.W.2d 861, 865 (Mo. banc 1987). When public officials perform purely ministerial duties, however, they may be held hable. Kanagawa, 685 S.W.2d at 835. A discretionary act requires “the exercise of reason in the adaptation of means to-an end and discretion in determining how or whether an act should be doné or course pursued.” Id. In contrast, ministerial acts “require certain duties to be performed ‘upon a given state of facts, in a prescribed manner, in obedience to the mandate of the legal authority, without regard to an employee’s own judgment or opinion concerning the propriety of the act to be performed.’” Jungerman v. City of Raytown, 925 S.W.2d 202, 205 (Mo. banc 1996). Determination of whether a public official’s acts are discretionary or ministerial rests upon the facts of the case. Kanagawa, 685 S.W.2d at 836. In making a determination, courts weigh factors such as “the nature of the official’s duties, the extent to which the acts involve policymaking or the exercise of professional expertise and *285judgment, and the likely consequences of withholding immunity.” Id.
The taxpayers assert that the board members are responsible only for “setting a tax rate ceiling and revising it each year.” They claim that the board members exercise no discretion in setting the highest lawful levy for each school district because section 137.073, RSMo and article X, section 22(a) provide specific direction to the board members in this regard.
The taxpayers are correct insofar as their claim extends. They ignore, however, other important activities in which board members engage in selecting the tax levy rate that is ultimately set for the school district. It is the entire process of selecting the levy rate upon which this Court focuses in determining whether the board members are entitled to official immunity, not merely the act of determining the highest lawful levy.
Viewing the levy-setting process as a whole - the selection of the operating levy for the district - it is evident that no legal mandate prevents the board members from exercising judgment regarding the levy rate that is ultimately set. Only the determination of the highest lawful levy, pursuant to section 137.073, RSMo, and article X, section 22(a), is prescribed by law. Beyond that, the board members must exercise discretion in setting a levy. Board members are under no obligation to levy the maximum ceiling rate. In setting the levy rate, they must exercise some degree of reason and judgment in deciding how to determine the district’s needs, and how to proceed once they ascertain those needs. Their actions are discretionary. As a consequence, they rightly claimed the protection of the doctrine of official immunity.
The taxpayers contend that even if the doctrine of official immunity applies, section 139.300.1, RSMo 1994, waives that immunity. Subsection 1 of section 139.300 provides:
Every county clerk, assessor, collector or other officer, who refuses or knowingly neglects to perform any duty enjoined on him by, or consents in or connives at any evasion of the laws relating to the assessment, levy and collection of taxes, whereby any proceedings required by such laws are prevented or hindered, or any property is unlawfully exempted from taxation or is entered upon the tax list at less than its full cash value, is liable for each offense, neglect or refusal, individually and on his official bond, for double the amount of the loss or damage caused thereby.
The taxpayers assert that subsection 1 “specifically waives any immunity of public officials with regard to illegal tax levies.” The entirety of their argument is: “As the Respondent School Board Members are ‘other officers’'who neglected to perform duties imposed upon them by the Missouri Constitution and statute with regard to tax levies, they cannot assert any immunity because Section 139.300.1 waives any immunity.”
The taxpayers fail to develop their assertion. It stands without reference to any legal authority and is devoid of analysis. Without more, this Court cannot provide meaningful appellate review. Missouri Ass’n of Counties v. Wilson, 3 S.W.3d 772, 775 (Mo. banc 1999). The trial court properly dismissed the individual school board members from the suits.
In conclusion, the schools were not entitled to summary judgments because the schools failed to prove that annual adjustments were not required to the maximum authorized current levy, under article X, section 22(a) for the years 1994,1995,1996, 1997, and 1998, and because the schools failed to prove that annual adjustments were not required to the tax rate ceiling under section 137.073, RSMo, for the years 1997 and 1998. As the analysis of the requirements of article X, section 22(a) and section 137.073, RSMo, reveals, the two provisions serve two related but different purposes. Article X, section 22(a) pro*286vides for a maximum authorized levy based on adjustments to the rate levied on November 4, 1980, unless the voters grant approval otherwise. See Fort Zumwalt Sch. Dist. v. State, 896 S.W.2d 918, 921 (Mo. banc 1995). The computation under article X, section 22(a) establishes the maximum amount that “could have been collected at the existing authorized levy on the prior assessed value.” Mo. Const. Art. X, section 22(a) (emphasis added). The tax rate ceiling under section 137.073, RSMo, meanwhile, is the amount that would “produce from all taxable property ... substantially the same amount of tax revenue as was produced in the previous year....” Section 137.073.2, RSMo (emphasis added). Although the formulas used to compute the two tax rate ceilings may involve some of the same variables, section 137.073, RSMo, and article X, section 22(a) may establish two distinct ceilings. See section 137.073.4(1), RSMo (differentiating between two distinct tax rate ceiling computations); section 137.037.4(2), RSMo (providing for computation of multiple tax rate ceilings “separately” and requiring the use of the “calculation that produces the lowest tax rate ceiling”). Pursuant to section 137.073.4(2), RSMo, the school districts are required to utilize the lowest tax rate ceiling as the highest lawful levy in the district. Under the legislative scheme, computing a separate tax rate ceiling pursuant to section 137.073, RSMo, will not violate the terms of article X, section 22(a) because the section 137.073, RSMo, tax rate ceiling will be used only if it is lower than that required by article X, section 22.
On remand, the parties may put on such additional proof as they deem necessary. The trial court should then determine for each of the five years in question the highest lawful levy and determine whether the taxpayers have proven that the schools assessed a levy in excess of the highest lawful levy.
The judgments are affirmed in part and reversed in part and the causes remanded for proceedings consistent with this opinion.
LIMBAUGH, WHITE, HOLSTEIN and BENTON, JJ., concur; PRICE, C.J., concurs in separate opinion filed; WOLFF, J., concurs in separate opinion filed.. The taxpayers in both cases style their petitions as class actions. The trial court, however, did not certify a class of plaintiffs in either case, nor does the record indicate that any non-parties were given notice. See Rule 52.08(c). There is, therefore, no class of plaintiffs, and the taxpayers do not challenge that conclusion.
. During the years at issue, there were two versions of the statutes in effect, found in RSMo 1994 and RSMo Supp.1996. Accordingly, references to RSMo will state the specific year as appropriate, or no year when referring to any section generally.
.During the years at issue, there were four versions of the relevant regulation and accompanying forms, with the following effective dates: August 6, 1992; November 30, 1994; June 24, 1996; and November 30, 1996.
. The taxpayers filed, in each case, a motion to file a supplemental legal file before this Court containing additional data. The motions are overruled because the data is not necessary to resolve the issue before the Court at this time.
. The schools contend that the taxpayers' briefs do not comply with Rules 84.04(d) and 84.04(i). This Court concludes that the briefs substantially comply with the requirements of the rules.
.The schools filed, in each of the cases below, a motion to dismiss for failure to state a claim. They attached to each motion the affidavit of Alex Bartlett, in which he lists the operating levies calculated by the Missouri State Board of Education for the years 1980 through 1983. Although the taxpayers filed, in each case, a motion to exclude Bartlett’s affidavit, they attached to their suggestions in opposition to the schools’ motions five exhibits of the schools’ tax rate worksheets deriving *282the tax rate to be levied in the years 1994 through 1998. Rule 55.27(a) authorizes the conversion of a motion to dismiss into a motion for summary judgment when parties present to the trial judge materials outside the pleadings. The trial court applied Rule 55.27(a) and found that it had provided adequate notice to the parties during a conference that matters outside the pleadings would be considered. In addition, the parties acquiesced in the treatment of the schools’ motions to dismiss as motions for summary judgment by providing to the trial court materials outside the pleadings. See Sale v. Slitz, 998 S.W.2d 159, 162 (Mo.App.1999). At the time the trial court entered summary judgment in the cases, the parties had not yet undertaken discovery.
. The trial court stated that the- taxpayers insufficiently pleaded their computations for the amounts they alleged as the highest lawful levy. The taxpayers did, however, allege amounts for the highest lawful levy based on the state auditor’s assessment and are entitled to put on their proof regarding the computation of those amounts. See Fort Zumwalt Sch. Dist. v. State, 896 S.W.2d 918, 922-923 (Mo. banc 1995); Gladis v. Rooney, 999 S.W.2d 288, 290 (Mo.App.1999) (reversing summary judgment entered based on the failure to state a claim).
. The parties assume, without briefing or argument, that the 1994 law (S.B.676) amending section 137.073 - effective July 12, 1994 - applies to the 1994 tax year.
. Both districts in this case set their 1996 levies before August 28, 1996. See sections 164.011 and 164.041, RSMo 1994. The 1996 amendment to section 137.073 - effective August 28, 1996 - does not apply to the 1996 tax year. See Beatty v. State Tax Comm’n, 912 S.W.2d 492, 496 & n. 1 (Mo. banc 1995).