On the occasion of the 7th anniversary of the 9/11 tragedy, I compared related terms:
Scale is based on the average worldwide traffic of "world trade center"... in all years
"world trade center"... 1.00
"flight 93" 0.10
As expected, all terms experience an annual Google-peak on the anniversaries, with 9/11 having an edge. Note the contrast between 2004 and 2008: in 2004, 9/11 invoked a lot of queries during the presidential elections campaign while now there's no such interest. Indeed, apart from a video at the Republican National Convention (which was widely criticized), there has been little direct mention of the events of 9/11 this year.
Update: I forgot about Rudy "A Noun, a Verb and 9/11" Giuliani during this year's early primaries. It really didn't rise to the level of four years ago though.
12 hours ago