-21.03% is the change from 870 to 687
Calculation steps:
[( 687 - 870 ) ÷ 870] x 100 = -21.03%
Formula
Percentage change = [(687 - 870) / 870] x 100
Subtract the new number by the original number
687 - 870 = -183
-183 ÷ 870 = -0.2103448275862069
-0.2103448275862069 x 100 = -21.03%