-98.4% is the change from 813 to 13
Calculation steps:
[( 13 - 813 ) ÷ 813] x 100 = -98.4%
Formula
Percentage change = [(13 - 813) / 813] x 100
Subtract the new number by the original number
13 - 813 = -800
-800 ÷ 813 = -0.984009840098401
-0.984009840098401 x 100 = -98.4%