(a) The commissioners shall one (1) time a year order the assessors to reassess the annual benefits of the district, provided there have been improvements made or improvements destroyed or removed from one (1) or more tracts of land in the district, making it necessary to have the annual benefits revised.
(b)
(1) Whereupon, it shall be the duty of the assessors to reassess the benefits of the district, and the annual benefits assessed may be raised or lowered as conditions of the property change.
(2) However, the annual benefits extended against any piece of property shall not be increased from the annual benefits originally extended unless improvements are made to the land that will be benefited by the red imported fire ant abatement services provided by the district.