-21.37% is the change from 847 to 666
Calculation steps:
[( 666 - 847 ) ÷ 847] x 100 = -21.37%
Formula
Percentage change = [(666 - 847) / 847] x 100
Subtract the new number by the original number
666 - 847 = -181
-181 ÷ 847 = -0.21369539551357733
-0.21369539551357733 x 100 = -21.37%