-31.6% is the change from 921 to 630
Calculation steps:
[( 630 - 921 ) ÷ 921] x 100 = -31.6%
Formula
Percentage change = [(630 - 921) / 921] x 100
Subtract the new number by the original number
630 - 921 = -291
-291 ÷ 921 = -0.31596091205211724
-0.31596091205211724 x 100 = -31.6%