-18.9% is the change from 418 to 339
Calculation steps:
[( 339 - 418 ) ÷ 418] x 100 = -18.9%
Formula
Percentage change = [(339 - 418) / 418] x 100
Subtract the new number by the original number
339 - 418 = -79
-79 ÷ 418 = -0.18899521531100477
-0.18899521531100477 x 100 = -18.9%