-99.16% is the change from 830 to 7
Calculation steps:
[( 7 - 830 ) ÷ 830] x 100 = -99.16%
Formula
Percentage change = [(7 - 830) / 830] x 100
Subtract the new number by the original number
7 - 830 = -823
-823 ÷ 830 = -0.9915662650602409
-0.9915662650602409 x 100 = -99.16%