-15.29% is the change from 909 to 770
Calculation steps:
[( 770 - 909 ) ÷ 909] x 100 = -15.29%
Formula
Percentage change = [(770 - 909) / 909] x 100
Subtract the new number by the original number
770 - 909 = -139
-139 ÷ 909 = -0.15291529152915292
-0.15291529152915292 x 100 = -15.29%