-29.89% is the change from 870 to 610
Calculation steps:
[( 610 - 870 ) ÷ 870] x 100 = -29.89%
Formula
Percentage change = [(610 - 870) / 870] x 100
Subtract the new number by the original number
610 - 870 = -260
-260 ÷ 870 = -0.2988505747126437
-0.2988505747126437 x 100 = -29.89%