-40.94% is the change from 850 to 502
Calculation steps:
[( 502 - 850 ) ÷ 850] x 100 = -40.94%
Formula
Percentage change = [(502 - 850) / 850] x 100
Subtract the new number by the original number
502 - 850 = -348
-348 ÷ 850 = -0.40941176470588236
-0.40941176470588236 x 100 = -40.94%