-86.56% is the change from 521 to 70
Calculation steps:
[( 70 - 521 ) ÷ 521] x 100 = -86.56%
Formula
Percentage change = [(70 - 521) / 521] x 100
Subtract the new number by the original number
70 - 521 = -451
-451 ÷ 521 = -0.8656429942418427
-0.8656429942418427 x 100 = -86.56%