-23.14% is the change from 821 to 631
Calculation steps:
[( 631 - 821 ) ÷ 821] x 100 = -23.14%
Formula
Percentage change = [(631 - 821) / 821] x 100
Subtract the new number by the original number
631 - 821 = -190
-190 ÷ 821 = -0.23142509135200975
-0.23142509135200975 x 100 = -23.14%