-61.33% is the change from 256 to 99
Calculation steps:
[( 99 - 256 ) ÷ 256] x 100 = -61.33%
Formula
Percentage change = [(99 - 256) / 256] x 100
Subtract the new number by the original number
99 - 256 = -157
-157 ÷ 256 = -0.61328125
-0.61328125 x 100 = -61.33%