-79.7% is the change from 665 to 135
Calculation steps:
[( 135 - 665 ) ÷ 665] x 100 = -79.7%
Formula
Percentage change = [(135 - 665) / 665] x 100
Subtract the new number by the original number
135 - 665 = -530
-530 ÷ 665 = -0.7969924812030075
-0.7969924812030075 x 100 = -79.7%