-0.82% is the change from 857 to 850
Calculation steps:
[( 850 - 857 ) ÷ 857] x 100 = -0.82%
Formula
Percentage change = [(850 - 857) / 857] x 100
Subtract the new number by the original number
850 - 857 = -7
-7 ÷ 857 = -0.008168028004667444
-0.008168028004667444 x 100 = -0.82%