-84.96% is the change from 665 to 100
Calculation steps:
[( 100 - 665 ) ÷ 665] x 100 = -84.96%
Formula
Percentage change = [(100 - 665) / 665] x 100
Subtract the new number by the original number
100 - 665 = -565
-565 ÷ 665 = -0.849624060150376
-0.849624060150376 x 100 = -84.96%