-98.15% is the change from 813 to 15
Calculation steps:
[( 15 - 813 ) ÷ 813] x 100 = -98.15%
Formula
Percentage change = [(15 - 813) / 813] x 100
Subtract the new number by the original number
15 - 813 = -798
-798 ÷ 813 = -0.981549815498155
-0.981549815498155 x 100 = -98.15%