-79.13% is the change from 666 to 139
Calculation steps:
[( 139 - 666 ) ÷ 666] x 100 = -79.13%
Formula
Percentage change = [(139 - 666) / 666] x 100
Subtract the new number by the original number
139 - 666 = -527
-527 ÷ 666 = -0.7912912912912913
-0.7912912912912913 x 100 = -79.13%