As a condition precedent to the exercise of the authority to levy the local income tax authorized by this article for the year following the initial year in which it is levied, the governing authority of each county and municipality receiving any proceeds from the tax shall adjust its mill rate for ad valorem taxation so that the aggregate revenue derived from ad valorem taxation by the county or municipality shall not exceed the total amount received by it from ad valorem taxation for the previous year less an amount which equals the net proceeds derived by the county or municipality from the local income tax imposed pursuant to this article during the previous year.