-28.62% is the change from 870 to 621
Calculation steps:
[( 621 - 870 ) ÷ 870] x 100 = -28.62%
Formula
Percentage change = [(621 - 870) / 870] x 100
Subtract the new number by the original number
621 - 870 = -249
-249 ÷ 870 = -0.28620689655172415
-0.28620689655172415 x 100 = -28.62%