-28.39% is the change from 870 to 623
Calculation steps:
[( 623 - 870 ) ÷ 870] x 100 = -28.39%
Formula
Percentage change = [(623 - 870) / 870] x 100
Subtract the new number by the original number
623 - 870 = -247
-247 ÷ 870 = -0.28390804597701147
-0.28390804597701147 x 100 = -28.39%