A city or town required by RCW 35.21.870(2) to reduce its rate of taxation on telephone business may defer for one year the required reduction in rates for the year 1987. If the delay in rate reductions authorized by the preceding sentence is inadequate for a city or town to offset the impact of revenue reductions arising from the removal of revenues from connecting fees, switching charges, or carrier access charges under the provisions of RCW 35.21.714, then the legislative body of such city or town may reimpose for 1987 the rates that such city or town had in effect upon telephone business during 1985. In each succeeding year, the city or town shall reduce the rate by one-tenth of the difference between the tax rate on April 20, 1982, and six percent.