-92.3% is the change from 857 to 66
Calculation steps:
[( 66 - 857 ) ÷ 857] x 100 = -92.3%
Formula
Percentage change = [(66 - 857) / 857] x 100
Subtract the new number by the original number
66 - 857 = -791
-791 ÷ 857 = -0.9229871645274212
-0.9229871645274212 x 100 = -92.3%