-36.9% is the change from 870 to 549
Calculation steps:
[( 549 - 870 ) ÷ 870] x 100 = -36.9%
Formula
Percentage change = [(549 - 870) / 870] x 100
Subtract the new number by the original number
549 - 870 = -321
-321 ÷ 870 = -0.3689655172413793
-0.3689655172413793 x 100 = -36.9%