@DeathByVisualStudio: The problem is we don't know what we are looking at, and that is pretty disconcerting.
For instance, what happened in 2004? The iPod, of course, so that has to be what makes Apple jump from 5% to 21%, but something else must have happened that year, to make "Others" jump from zilch to 29%. I cannot remember what might have been so big to make more of a splash than the iPod, maybe it was a number of things, but I cannot really figure this out (unless some specific OS, e.g. Symbian, got "computing device" status in 2004).
Another disconcerting fact is that Apple stays almost flat after 2004, in the 20's range; flat enough that it's impossible to say when the iPhone or the iPad were introduced in this timeline. Of course the PC business have been growing in the double digits until very recently, so the graph is kind of skewed, but I was still taken by surprise.
We have an important milestone for our comparisons: 2008. That's when, according to Gartner, the 1 billion PC mark was reached. According to those percentages, there were roughly 500 million Apple devices back then (Mac + iPod + iPhone); and there were about 650 million "Others" devices. Any clue as to what those are supposed to be?
Fast forward a few years; as I mentioned the PC market keeps growing until very recently, so that billion must have grown significantly, but let's keep it as it's a nice round figure. If PC's are 20% (and that's our conservative estimate of one billion units), there are more than one billion Apple devices out there and more than two billion Android devices (plus the usual 700 million unknown "Others"). Does that even remotely sounds possible? Android gets there in just 4 years, which means that, assuming linear growth, they must have sold some 500 million units per year (without any turnover: every unit sold goes to a new customer).
The chart isn't bogus, of course, and is probably indicating something important. What I know is it's probably not numbers that can be compared to net applications or similar statistics. Maybe it's units sold that year, maybe it's revenues. Without proper labeling and some background information, any number means pretty much anything.