-12.88% is the change from 815 to 710
Calculation steps:
[( 710 - 815 ) ÷ 815] x 100 = -12.88%
Formula
Percentage change = [(710 - 815) / 815] x 100
Subtract the new number by the original number
710 - 815 = -105
-105 ÷ 815 = -0.12883435582822086
-0.12883435582822086 x 100 = -12.88%