More Information Than You Could Ever Possibly Require

Google launched its latest gadget a while ago, the Google Ngram Viewer. Using the viewer, you can compare the frequency of word usage on Google Books. For instance, want to see how often the word "kayak" was in used in books during the time from 1900 to present? Just stick in the word "kayak" and ta-da!

We can see that usage of the word kayak has gone up over the last 20 years or so, not a surprise since the usage of actual kayaks has increased over that time. Interestingly, there's quite a big spike in usage in the mid-1930s as well. And if we go back another century as per the graph below...

...we can see large spikes in usage around 1870 and 1895.
The first usage seems to be around 1817. My guess is the first usage was either a typo or was a writer trying to describe the sound a cat makes when it coughs up a hairball.
How does "kayak" compare with other phrases or words? I chose another word and phrase at random, and the results are below.

Not surprisingly "kayak" rated higher than "aardvark," but interestingly "kayak" rated much higher than "Captain Kirk." Perhaps most shocking of all, it took "Captain Kirk" until the mid-1980s to pass "aardvark" in usage.
And I know what you're all wondering so here it is. Wonder no more.