-41.38% is the change from 870 to 510
Calculation steps:
[( 510 - 870 ) ÷ 870] x 100 = -41.38%
Formula
Percentage change = [(510 - 870) / 870] x 100
Subtract the new number by the original number
510 - 870 = -360
-360 ÷ 870 = -0.41379310344827586
-0.41379310344827586 x 100 = -41.38%