score:13
According to Google Ngram Viewer, the words have some historical usage.
However, it is hard to know whether the words refer to decades, age groups or other "brackets". However, "eighties" and "nineties" do show some sort of a 100-year wave shape, taking off from around 1890, suggesting that the usage of these phrases started around then. There is a wave shape for all words except "twenties" and "thirties" which seem to mainly be used for the 1920s and 1930s.
Clicking on the year search terms at the bottom of the Ngram page linked above suggests mixed usage with at least some decade references for the 90s as 1890s (the only Google Books search I tried)
See also the Wikipedia article http://en.wikipedia.org/wiki/List_of_decades which has a brief description of naming, as well as links to articles on individual decades (such as the 1890s)
Upvote:2
In one of Kipling's short stories he refers back to the '60s - 1860s. If such a conventional man did so, it must have been commonplace, at least among the British in India.
Upvote:9
One example: the wave of German (and other European) immigrants that came to the United States in 1848 were referred to as the "Forty-Eighters."
And the gold miners who went to California in 1849 were known as the "Forty-niners."
So yes, each century refers to their own contemporaneous "Forties," "Fifties," etc.