-81.93% is the change from 830 to 150
Calculation steps:
[( 150 - 830 ) ÷ 830] x 100 = -81.93%
Formula
Percentage change = [(150 - 830) / 830] x 100
Subtract the new number by the original number
150 - 830 = -680
-680 ÷ 830 = -0.8192771084337349
-0.8192771084337349 x 100 = -81.93%