-10.78% is the change from 102 to 91
Calculation steps:
[( 91 - 102 ) ÷ 102] x 100 = -10.78%
Formula
Percentage change = [(91 - 102) / 102] x 100
Subtract the new number by the original number
91 - 102 = -11
-11 ÷ 102 = -0.10784313725490197
-0.10784313725490197 x 100 = -10.78%