-73.62% is the change from 815 to 215
Calculation steps:
[( 215 - 815 ) ÷ 815] x 100 = -73.62%
Formula
Percentage change = [(215 - 815) / 815] x 100
Subtract the new number by the original number
215 - 815 = -600
-600 ÷ 815 = -0.7361963190184049
-0.7361963190184049 x 100 = -73.62%