-90.84% is the change from 993 to 91
Calculation steps:
[( 91 - 993 ) ÷ 993] x 100 = -90.84%
Formula
Percentage change = [(91 - 993) / 993] x 100
Subtract the new number by the original number
91 - 993 = -902
-902 ÷ 993 = -0.9083585095669687
-0.9083585095669687 x 100 = -90.84%