-79.25% is the change from 670 to 139
Calculation steps:
[( 139 - 670 ) ÷ 670] x 100 = -79.25%
Formula
Percentage change = [(139 - 670) / 670] x 100
Subtract the new number by the original number
139 - 670 = -531
-531 ÷ 670 = -0.7925373134328358
-0.7925373134328358 x 100 = -79.25%