Named Dragons

[Havard]

Is there a way to determine the age of these dragons in years? How old is a Very Old Black Dragon?

Found this from a 3E SRD site:
Category Age (Years)
1 Wyrmling 0–5
2 Very young 6–15
3 Young 16–25
4 Juvenile 26–50
5 Young adult 51–100
6 Adult 101–200
7 Mature adult 201–400
8 Old 401–600
9 Very old 601–800
10 Ancient 801–1,000
11 Wyrm 1,001–1,200
12 Great wyrm 1,201 or more

-Havard