Mo. Rev. Stat. § 136.400
The excess revenue to be refunded shall include all revenue in excess of the limit established in Article X, Section 18, Paragraph (a) of the Missouri Constitution collected during a fiscal year. The office of administration shall certify the amount of excess revenue to be refunded and certify annually to the general assembly in itemized list and definition of all sources and dollar amounts of total state revenue. Once a source of revenue has been certified as total state revenue by the office of administration, such source shall remain total state revenue in subsequent years unless the source is* subsequently excluded from total state revenue pursuant to Article X, Section 18(c) of the Missouri Constitution. The amount of excess revenue to be refunded is subject to appeal according to Article X, Section 23 of the Missouri Constitution.
§ 136.400, RSMo