-20.14% is the change from 834 to 666
Calculation steps:
[( 666 - 834 ) ÷ 834] x 100 = -20.14%
Formula
Percentage change = [(666 - 834) / 834] x 100
Subtract the new number by the original number
666 - 834 = -168
-168 ÷ 834 = -0.2014388489208633
-0.2014388489208633 x 100 = -20.14%