-39.61% is the change from 861 to 520
Calculation steps:
[( 520 - 861 ) ÷ 861] x 100 = -39.61%
Formula
Percentage change = [(520 - 861) / 861] x 100
Subtract the new number by the original number
520 - 861 = -341
-341 ÷ 861 = -0.39605110336817656
-0.39605110336817656 x 100 = -39.61%