-30% is the change from 130 to 91
Calculation steps:
[( 91 - 130 ) ÷ 130] x 100 = -30%
Formula
Percentage change = [(91 - 130) / 130] x 100
Subtract the new number by the original number
91 - 130 = -39
-39 ÷ 130 = -0.3
-0.3 x 100 = -30%
Example