-88.1% is the change from 815 to 97
Calculation steps:
[( 97 - 815 ) ÷ 815] x 100 = -88.1%
Formula
Percentage change = [(97 - 815) / 815] x 100
Subtract the new number by the original number
97 - 815 = -718
-718 ÷ 815 = -0.8809815950920246
-0.8809815950920246 x 100 = -88.1%