Mo. Rev. Stat. § 321.221
The amount to be paid annually by the municipality to the fire district pursuant to subdivision (16) of section 321.220 shall be the annual assessed value of all property subject to tax in the municipality determined from the tax assessment ledgers, and including public utilities and intangible property within such area, multiplied by the annual tax rate as certified by the fire protection district to the municipality (but not including any portion of the tax rate for ambulance service provided by the district) per one hundred dollars of assessed value in such area. The tax rate so computed shall include any tax on bonded indebtedness incurred by the district prior to entering into such contract, but shall not include any of the tax rate for bonded indebtedness incurred during the term that the contract is in force.
§ 321.221, RSMo