-99.51% is the change from 815 to 4
Calculation steps:
[( 4 - 815 ) ÷ 815] x 100 = -99.51%
Formula
Percentage change = [(4 - 815) / 815] x 100
Subtract the new number by the original number
4 - 815 = -811
-811 ÷ 815 = -0.9950920245398773
-0.9950920245398773 x 100 = -99.51%