What an unimaginative infographic Original by Phil Gyford, rearranged by Paul Mison [via].

Might it have something to do with this?

Here’s the other end of the spectrum. (I tried to do this recently with books: pages-per-day estimated from page counts and start/finish reading dates. Scrapped the project for a number of reasons: (a) I had to fill in pagecount manually, (b) my reading records were patchy and have since gotten even patchier, (c) given a small data set and not much continuity (tendency to finish one book before starting the next) the colours are not as informative and interesting, and (d) my attempt at making graphed area precisely informative turned out more confusing than I expected.)