I sometimes use Google's "Ngrams" feature to dredge up old writings on Epicureanism. Today I decided to do a few comparative searches.
Here's how this works; you enter a search term, and google scans through an enormous quantity of digitized books and newspapers published over the last two hundred years. The data is then plotted on a line graph. I don't know how much we can really glean from this data, since it's plagued by inevitable errors (text-scanning a photocopy is hideously inaccurate), and also inevitable omissions and biases (presumably works still under copyright are excluded, for example). Nevertheless, here are a few eye-catching comparisons: