-78.79% is the change from 660 to 140
Calculation steps:
[( 140 - 660 ) ÷ 660] x 100 = -78.79%
Formula
Percentage change = [(140 - 660) / 660] x 100
Subtract the new number by the original number
140 - 660 = -520
-520 ÷ 660 = -0.7878787878787878
-0.7878787878787878 x 100 = -78.79%