-21% is the change from 857 to 677
Calculation steps:
[( 677 - 857 ) ÷ 857] x 100 = -21%
Formula
Percentage change = [(677 - 857) / 857] x 100
Subtract the new number by the original number
677 - 857 = -180
-180 ÷ 857 = -0.2100350058343057
-0.2100350058343057 x 100 = -21%