-30% is the change from 580 to 406
Calculation steps:
[( 406 - 580 ) ÷ 580] x 100 = -30%
Formula
Percentage change = [(406 - 580) / 580] x 100
Subtract the new number by the original number
406 - 580 = -174
-174 ÷ 580 = -0.3
-0.3 x 100 = -30%
Example