-4.32% is the change from 857 to 820
Calculation steps:
[( 820 - 857 ) ÷ 857] x 100 = -4.32%
Formula
Percentage change = [(820 - 857) / 857] x 100
Subtract the new number by the original number
820 - 857 = -37
-37 ÷ 857 = -0.043173862310385065
-0.043173862310385065 x 100 = -4.32%