-30.98% is the change from 936 to 646
Calculation steps:
[( 646 - 936 ) ÷ 936] x 100 = -30.98%
Formula
Percentage change = [(646 - 936) / 936] x 100
Subtract the new number by the original number
646 - 936 = -290
-290 ÷ 936 = -0.30982905982905984
-0.30982905982905984 x 100 = -30.98%