-20.84% is the change from 830 to 657
Calculation steps:
[( 657 - 830 ) ÷ 830] x 100 = -20.84%
Formula
Percentage change = [(657 - 830) / 830] x 100
Subtract the new number by the original number
657 - 830 = -173
-173 ÷ 830 = -0.20843373493975903
-0.20843373493975903 x 100 = -20.84%