-85.15% is the change from 815 to 121
Calculation steps:
[( 121 - 815 ) ÷ 815] x 100 = -85.15%
Formula
Percentage change = [(121 - 815) / 815] x 100
Subtract the new number by the original number
121 - 815 = -694
-694 ÷ 815 = -0.8515337423312883
-0.8515337423312883 x 100 = -85.15%