-71.57% is the change from 830 to 236
Calculation steps:
[( 236 - 830 ) ÷ 830] x 100 = -71.57%
Formula
Percentage change = [(236 - 830) / 830] x 100
Subtract the new number by the original number
236 - 830 = -594
-594 ÷ 830 = -0.7156626506024096
-0.7156626506024096 x 100 = -71.57%