"Ideal" body fat percentages by age

[chesspain]

I'm six feet tall and nearly forty-four years old, and in the five months since I've been exercising and eating healthier, I've brought my weight down from 205 lbs to 182 lbs, with a current body fat percentage of approx. 18%. Although I certainly feel and look better, I still have a bit of a spare tire around my waist. While checking for body fat range charts, I found a couple of sites with tables similar to the one below:

MALE
Age Excellent Good Fair Poor
19-24 10.8 % 14.9 % 19.0 % 23.3 %
25-29 12.8 % 16.5 % 20.3 % 24.4 %
30-34 14.5 % 18.0 % 21.5 % 25.2 %
35-39 16.1 % 19.4 % 22.6 % 26.1 %
<font color="blue"> 40-44 17.5 % 20.5 % 23.6 % 26.9 % </font>
45-49 18.6 % 21.5 % 24.5 % 27.6 %
50-54 19.8 % 22.7 % 25.6 % 28.7 %
55-59 20.2 % 23.2 % 26.2 % 29.3 %
60 + 20.3 % 23.5 % 26.7 % 29.8

And I see that for my age, my body fat percentage is considered nearly excellent ("ideal" according to another table I saw). However, I'm obviously kind of far from lean.

Do these charts consider someone my age and bf percentage "excellent/ideal" because so many middle-age men are overweight, or are there biologically imposed barriers to how lean someone can reasonably expect to be as they get older?