-18.08% is the change from 636 to 521
Calculation steps:
[( 521 - 636 ) ÷ 636] x 100 = -18.08%
Formula
Percentage change = [(521 - 636) / 636] x 100
Subtract the new number by the original number
521 - 636 = -115
-115 ÷ 636 = -0.18081761006289307
-0.18081761006289307 x 100 = -18.08%