-90.62% is the change from 970 to 91
Calculation steps:
[( 91 - 970 ) ÷ 970] x 100 = -90.62%
Formula
Percentage change = [(91 - 970) / 970] x 100
Subtract the new number by the original number
91 - 970 = -879
-879 ÷ 970 = -0.9061855670103093
-0.9061855670103093 x 100 = -90.62%