-21.78% is the change from 877 to 686
Calculation steps:
[( 686 - 877 ) ÷ 877] x 100 = -21.78%
Formula
Percentage change = [(686 - 877) / 877] x 100
Subtract the new number by the original number
686 - 877 = -191
-191 ÷ 877 = -0.217787913340935
-0.217787913340935 x 100 = -21.78%