-74.63% is the change from 670 to 170
Calculation steps:
[( 170 - 670 ) ÷ 670] x 100 = -74.63%
Formula
Percentage change = [(170 - 670) / 670] x 100
Subtract the new number by the original number
170 - 670 = -500
-500 ÷ 670 = -0.746268656716418
-0.746268656716418 x 100 = -74.63%