-23.56% is the change from 815 to 623
Calculation steps:
[( 623 - 815 ) ÷ 815] x 100 = -23.56%
Formula
Percentage change = [(623 - 815) / 815] x 100
Subtract the new number by the original number
623 - 815 = -192
-192 ÷ 815 = -0.23558282208588957
-0.23558282208588957 x 100 = -23.56%