-4.71% is the change from 870 to 829
Calculation steps:
[( 829 - 870 ) ÷ 870] x 100 = -4.71%
Formula
Percentage change = [(829 - 870) / 870] x 100
Subtract the new number by the original number
829 - 870 = -41
-41 ÷ 870 = -0.047126436781609195
-0.047126436781609195 x 100 = -4.71%