-31.06% is the change from 966 to 666
Calculation steps:
[( 666 - 966 ) ÷ 966] x 100 = -31.06%
Formula
Percentage change = [(666 - 966) / 966] x 100
Subtract the new number by the original number
666 - 966 = -300
-300 ÷ 966 = -0.3105590062111801
-0.3105590062111801 x 100 = -31.06%