-24.02% is the change from 820 to 623
Calculation steps:
[( 623 - 820 ) ÷ 820] x 100 = -24.02%
Formula
Percentage change = [(623 - 820) / 820] x 100
Subtract the new number by the original number
623 - 820 = -197
-197 ÷ 820 = -0.24024390243902438
-0.24024390243902438 x 100 = -24.02%