-90.5% is the change from 221 to 21
Calculation steps:
[( 21 - 221 ) ÷ 221] x 100 = -90.5%
Formula
Percentage change = [(21 - 221) / 221] x 100
Subtract the new number by the original number
21 - 221 = -200
-200 ÷ 221 = -0.9049773755656109
-0.9049773755656109 x 100 = -90.5%