-81.57% is the change from 830 to 153
Calculation steps:
[( 153 - 830 ) ÷ 830] x 100 = -81.57%
Formula
Percentage change = [(153 - 830) / 830] x 100
Subtract the new number by the original number
153 - 830 = -677
-677 ÷ 830 = -0.8156626506024096
-0.8156626506024096 x 100 = -81.57%