-99.14% is the change from 815 to 7
Calculation steps:
[( 7 - 815 ) ÷ 815] x 100 = -99.14%
Formula
Percentage change = [(7 - 815) / 815] x 100
Subtract the new number by the original number
7 - 815 = -808
-808 ÷ 815 = -0.9914110429447853
-0.9914110429447853 x 100 = -99.14%