-20% is the change from 505 to 404
Calculation steps:
[( 404 - 505 ) ÷ 505] x 100 = -20%
Formula
Percentage change = [(404 - 505) / 505] x 100
Subtract the new number by the original number
404 - 505 = -101
-101 ÷ 505 = -0.2
-0.2 x 100 = -20%
Example