-47.06% is the change from 850 to 450
Calculation steps:
[( 450 - 850 ) ÷ 850] x 100 = -47.06%
Formula
Percentage change = [(450 - 850) / 850] x 100
Subtract the new number by the original number
450 - 850 = -400
-400 ÷ 850 = -0.47058823529411764
-0.47058823529411764 x 100 = -47.06%