-40.54% is the change from 851 to 506
Calculation steps:
[( 506 - 851 ) ÷ 851] x 100 = -40.54%
Formula
Percentage change = [(506 - 851) / 851] x 100
Subtract the new number by the original number
506 - 851 = -345
-345 ÷ 851 = -0.40540540540540543
-0.40540540540540543 x 100 = -40.54%