Reminded of a post from last year by this parenthetical remark:
The paper also tracked word usage through time (each year, for instance, 1% of the world's English-speaking population switches from "sneaked" to "snuck").
The above appears in a WSJ piece about a recently published journal article, "Statistical Laws Governing Fluctuations in Word Use from Word Birth to Word Death." The paper's authors used the database created by Google's massive book-scanning effort and looked at the English, Spanish, and Hebrew languages.
A pre-print version of the paper is also available on arXiv, in case the first one above becomes inaccessible. As of this moment, you can read the whole thing online at the first link, and download a PDF from either.