-16.25% is the change from 991 to 830
Calculation steps:
[( 830 - 991 ) ÷ 991] x 100 = -16.25%
Formula
Percentage change = [(830 - 991) / 991] x 100
Subtract the new number by the original number
830 - 991 = -161
-161 ÷ 991 = -0.16246215943491424
-0.16246215943491424 x 100 = -16.25%