-99.01% is the change from 505 to 5
Calculation steps:
[( 5 - 505 ) ÷ 505] x 100 = -99.01%
Formula
Percentage change = [(5 - 505) / 505] x 100
Subtract the new number by the original number
5 - 505 = -500
-500 ÷ 505 = -0.9900990099009901
-0.9900990099009901 x 100 = -99.01%