Elf years to Human years ratio

[Maerbenn]

The Professor's last conception was that Elves become adults at the age of 3000:

HoMe X, 'Myths Transformed'
On Earth while an elf-child did but grow to be a man or a woman, in some 3000 years, forests would rise and fall, and all the face of the land would change, while birds and flowers innumerable would be born and die in löar upon löar under the wheeling Sun.