-18.1% is the change from 221 to 181
Calculation steps:
[( 181 - 221 ) ÷ 221] x 100 = -18.1%
Formula
Percentage change = [(181 - 221) / 221] x 100
Subtract the new number by the original number
181 - 221 = -40
-40 ÷ 221 = -0.18099547511312217
-0.18099547511312217 x 100 = -18.1%