-27.65% is the change from 857 to 620
Calculation steps:
[( 620 - 857 ) ÷ 857] x 100 = -27.65%
Formula
Percentage change = [(620 - 857) / 857] x 100
Subtract the new number by the original number
620 - 857 = -237
-237 ÷ 857 = -0.2765460910151692
-0.2765460910151692 x 100 = -27.65%