-21.01% is the change from 871 to 688
Calculation steps:
[( 688 - 871 ) ÷ 871] x 100 = -21.01%
Formula
Percentage change = [(688 - 871) / 871] x 100
Subtract the new number by the original number
688 - 871 = -183
-183 ÷ 871 = -0.21010332950631458
-0.21010332950631458 x 100 = -21.01%