-86.37% is the change from 521 to 71
Calculation steps:
[( 71 - 521 ) ÷ 521] x 100 = -86.37%
Formula
Percentage change = [(71 - 521) / 521] x 100
Subtract the new number by the original number
71 - 521 = -450
-450 ÷ 521 = -0.8637236084452975
-0.8637236084452975 x 100 = -86.37%