-39.42% is the change from 860 to 521
Calculation steps:
[( 521 - 860 ) ÷ 860] x 100 = -39.42%
Formula
Percentage change = [(521 - 860) / 860] x 100
Subtract the new number by the original number
521 - 860 = -339
-339 ÷ 860 = -0.3941860465116279
-0.3941860465116279 x 100 = -39.42%