-65.63% is the change from 643 to 221
Calculation steps:
[( 221 - 643 ) ÷ 643] x 100 = -65.63%
Formula
Percentage change = [(221 - 643) / 643] x 100
Subtract the new number by the original number
221 - 643 = -422
-422 ÷ 643 = -0.656298600311042
-0.656298600311042 x 100 = -65.63%