-0.78% is the change from 258 to 256
Calculation steps:
[( 256 - 258 ) ÷ 258] x 100 = -0.78%
Formula
Percentage change = [(256 - 258) / 258] x 100
Subtract the new number by the original number
256 - 258 = -2
-2 ÷ 258 = -0.007751937984496124
-0.007751937984496124 x 100 = -0.78%