-20.17% is the change from 828 to 661
Calculation steps:
[( 661 - 828 ) ÷ 828] x 100 = -20.17%
Formula
Percentage change = [(661 - 828) / 828] x 100
Subtract the new number by the original number
661 - 828 = -167
-167 ÷ 828 = -0.20169082125603865
-0.20169082125603865 x 100 = -20.17%