Our readers — and contributors — are apt to elect a good deal according to years. The seventies and eighties, we may suppose, are concerned for the large educational and cultural interests of their Alma Mater; the nineties are deep in the practical and business activities; the noughties are not naughty, but still young enough to sport a fantastic costume at reunion and let the college wag as it will; the oneties are the really wise as to what the college ought to be, especially on its athletic side, but as contributors modest.
Source: wiktionary