-74.91% is the change from 857 to 215
Calculation steps:
[( 215 - 857 ) ÷ 857] x 100 = -74.91%
Formula
Percentage change = [(215 - 857) / 857] x 100
Subtract the new number by the original number
215 - 857 = -642
-642 ÷ 857 = -0.7491248541423571
-0.7491248541423571 x 100 = -74.91%