-83.09% is the change from 538 to 91
Calculation steps:
[( 91 - 538 ) ÷ 538] x 100 = -83.09%
Formula
Percentage change = [(91 - 538) / 538] x 100
Subtract the new number by the original number
91 - 538 = -447
-447 ÷ 538 = -0.8308550185873605
-0.8308550185873605 x 100 = -83.09%