-12.93% is the change from 936 to 815
Calculation steps:
[( 815 - 936 ) ÷ 936] x 100 = -12.93%
Formula
Percentage change = [(815 - 936) / 936] x 100
Subtract the new number by the original number
815 - 936 = -121
-121 ÷ 936 = -0.12927350427350429
-0.12927350427350429 x 100 = -12.93%