-20.58% is the change from 656 to 521
Calculation steps:
[( 521 - 656 ) ÷ 656] x 100 = -20.58%
Formula
Percentage change = [(521 - 656) / 656] x 100
Subtract the new number by the original number
521 - 656 = -135
-135 ÷ 656 = -0.20579268292682926
-0.20579268292682926 x 100 = -20.58%