-50.18% is the change from 857 to 427
Calculation steps:
[( 427 - 857 ) ÷ 857] x 100 = -50.18%
Formula
Percentage change = [(427 - 857) / 857] x 100
Subtract the new number by the original number
427 - 857 = -430
-430 ÷ 857 = -0.5017502917152858
-0.5017502917152858 x 100 = -50.18%