Section 18 Excess Capital Gains Rolling Average

          Said section 5G of said chapter 29, as so appearing, is hereby amended by striking out, in lines 16 to 19, inclusive, the words "average annual rate of growth in United States gross domestic product over the preceding 5 years based on the most recently available data published by the Bureau of Economic Analysis in the United States Department of Commerce" and inserting in place thereof the following words:- 95 per cent of the average of final certified capital gains tax revenues for the prior 10 fiscal years, including the most recently ended fiscal year, adjusted for inflation based on the most recently available national gross domestic product price index data published by the Bureau of Economic Analysis in the federal Department of Commerce.

This section updates the methodology to calculate the annual excess capital gains threshold adjustment.