-49.65% is the change from 850 to 428
Calculation steps:
[( 428 - 850 ) ÷ 850] x 100 = -49.65%
Formula
Percentage change = [(428 - 850) / 850] x 100
Subtract the new number by the original number
428 - 850 = -422
-422 ÷ 850 = -0.4964705882352941
-0.4964705882352941 x 100 = -49.65%