-19.97% is the change from 651 to 521
Calculation steps:
[( 521 - 651 ) ÷ 651] x 100 = -19.97%
Formula
Percentage change = [(521 - 651) / 651] x 100
Subtract the new number by the original number
521 - 651 = -130
-130 ÷ 651 = -0.19969278033794163
-0.19969278033794163 x 100 = -19.97%