-56.75% is the change from 511 to 221
Calculation steps:
[( 221 - 511 ) ÷ 511] x 100 = -56.75%
Formula
Percentage change = [(221 - 511) / 511] x 100
Subtract the new number by the original number
221 - 511 = -290
-290 ÷ 511 = -0.5675146771037182
-0.5675146771037182 x 100 = -56.75%