-39.45% is the change from 109 to 66
Calculation steps:
[( 66 - 109 ) ÷ 109] x 100 = -39.45%
Formula
Percentage change = [(66 - 109) / 109] x 100
Subtract the new number by the original number
66 - 109 = -43
-43 ÷ 109 = -0.3944954128440367
-0.3944954128440367 x 100 = -39.45%