-16.83% is the change from 505 to 420
Calculation steps:
[( 420 - 505 ) ÷ 505] x 100 = -16.83%
Formula
Percentage change = [(420 - 505) / 505] x 100
Subtract the new number by the original number
420 - 505 = -85
-85 ÷ 505 = -0.16831683168316833
-0.16831683168316833 x 100 = -16.83%