-7.01% is the change from 870 to 809
Calculation steps:
[( 809 - 870 ) ÷ 870] x 100 = -7.01%
Formula
Percentage change = [(809 - 870) / 870] x 100
Subtract the new number by the original number
809 - 870 = -61
-61 ÷ 870 = -0.07011494252873564
-0.07011494252873564 x 100 = -7.01%