-38.78% is the change from 851 to 521
Calculation steps:
[( 521 - 851 ) ÷ 851] x 100 = -38.78%
Formula
Percentage change = [(521 - 851) / 851] x 100
Subtract the new number by the original number
521 - 851 = -330
-330 ÷ 851 = -0.38777908343125733
-0.38777908343125733 x 100 = -38.78%