-31.78% is the change from 947 to 646
Calculation steps:
[( 646 - 947 ) ÷ 947] x 100 = -31.78%
Formula
Percentage change = [(646 - 947) / 947] x 100
Subtract the new number by the original number
646 - 947 = -301
-301 ÷ 947 = -0.31784582893347413
-0.31784582893347413 x 100 = -31.78%