Yes, I'm sure there are other factors but the graph tells a pretty simple story. Numbers declined from 2005-2009, which means students that entered college around 2001-2005 -- students that were in high school during the dotcom bubble burst and aftermath. CS may not have seemed like an attractive field at the time. Over time the state of the field has recovered, and as you point out continued to grow and get more interesting, and growth in graduates returned.
Interestingly there is also a giant bubble at 1985-86 which wasn't match until around 2010.
Looking at
http://www.computerhistory.org/timeline/1982/ shows a couple of noteworthy events (Tron and the commodore 64).
Perhaps the difficulty combined with the ability to more easily detect cheating/being easier to cheat in the classes are contributing to a slower than desired growth. Given that when plotted out computer science appears to be one growing faster than many others suggests that it isn't that few people major, it's that the science is new and barriers to entry are high? (Annecdotally I know my college had additional barriers to pursuing CS focused on pre-reqs and grades, it's possible a lack of quality CS teachers is causing this as it is so new.)
right on the money. I graduated HS in 2004. I originally was into making websites in HS. the farthest I got was a little ASP and ColdFusion. But it didn't seem like a safe industry at the time so I went another direction. (but what did I know, I was a kid)
I never really made the connection of "building websites" to actual computer programming, so CS didn't even come up for me.
but now its 2017 and I went back to school and just graduated with a degree in CS.
