-2.71% is the change from 850 to 827
Calculation steps:
[( 827 - 850 ) ÷ 850] x 100 = -2.71%
Formula
Percentage change = [(827 - 850) / 850] x 100
Subtract the new number by the original number
827 - 850 = -23
-23 ÷ 850 = -0.027058823529411764
-0.027058823529411764 x 100 = -2.71%