-87.38% is the change from 721 to 91
Calculation steps:
[( 91 - 721 ) ÷ 721] x 100 = -87.38%
Formula
Percentage change = [(91 - 721) / 721] x 100
Subtract the new number by the original number
91 - 721 = -630
-630 ÷ 721 = -0.8737864077669902
-0.8737864077669902 x 100 = -87.38%