-5.88% is the change from 850 to 800
Calculation steps:
[( 800 - 850 ) ÷ 850] x 100 = -5.88%
Formula
Percentage change = [(800 - 850) / 850] x 100
Subtract the new number by the original number
800 - 850 = -50
-50 ÷ 850 = -0.058823529411764705
-0.058823529411764705 x 100 = -5.88%