-65.79% is the change from 646 to 221
Calculation steps:
[( 221 - 646 ) ÷ 646] x 100 = -65.79%
Formula
Percentage change = [(221 - 646) / 646] x 100
Subtract the new number by the original number
221 - 646 = -425
-425 ÷ 646 = -0.6578947368421053
-0.6578947368421053 x 100 = -65.79%