-90.32% is the change from 217 to 21
Calculation steps:
[( 21 - 217 ) ÷ 217] x 100 = -90.32%
Formula
Percentage change = [(21 - 217) / 217] x 100
Subtract the new number by the original number
21 - 217 = -196
-196 ÷ 217 = -0.9032258064516129
-0.9032258064516129 x 100 = -90.32%