-9.65% is the change from 850 to 768
Calculation steps:
[( 768 - 850 ) ÷ 850] x 100 = -9.65%
Formula
Percentage change = [(768 - 850) / 850] x 100
Subtract the new number by the original number
768 - 850 = -82
-82 ÷ 850 = -0.09647058823529411
-0.09647058823529411 x 100 = -9.65%