-28.93% is the change from 909 to 646
Calculation steps:
[( 646 - 909 ) ÷ 909] x 100 = -28.93%
Formula
Percentage change = [(646 - 909) / 909] x 100
Subtract the new number by the original number
646 - 909 = -263
-263 ÷ 909 = -0.2893289328932893
-0.2893289328932893 x 100 = -28.93%