I don't know if anyone has played around with Google Trends, but it gives you information about how certain search terms have trended over the last 8 years.
I found the one on
orienteering especially interesting, since we're see a definite negative trend here in the US (and worldwide).
You can compare any search terms against each other, and for any region. For comparison, I've seen a similar decline for "adventure race" and "adventure racing", and increases in "trail running" and "mud run".
I should note that what you ask for now may show up as
not enough search volume to show graphs, but if you do the same search again a few hours later, you'll see results (some of this data wasn't available when I looked for it last night, but it's there today).