-31.49% is the change from 921 to 631
Calculation steps:
[( 631 - 921 ) ÷ 921] x 100 = -31.49%
Formula
Percentage change = [(631 - 921) / 921] x 100
Subtract the new number by the original number
631 - 921 = -290
-290 ÷ 921 = -0.31487513572204123
-0.31487513572204123 x 100 = -31.49%