-39.63% is the change from 863 to 521
Calculation steps:
[( 521 - 863 ) ÷ 863] x 100 = -39.63%
Formula
Percentage change = [(521 - 863) / 863] x 100
Subtract the new number by the original number
521 - 863 = -342
-342 ÷ 863 = -0.3962920046349942
-0.3962920046349942 x 100 = -39.63%