-20.85% is the change from 657 to 520
Calculation steps:
[( 520 - 657 ) ÷ 657] x 100 = -20.85%
Formula
Percentage change = [(520 - 657) / 657] x 100
Subtract the new number by the original number
520 - 657 = -137
-137 ÷ 657 = -0.2085235920852359
-0.2085235920852359 x 100 = -20.85%