I find it rather strange that they count Android as one category but break iOS into iPhone, iPad, and ObjectiveC. It'd be nice to know what the platform numbers are.
They're also trying to extrapolate to the end of 2012 (17 months away!), and they're only counting freelancing jobs (which needs to be reflected in the title, OP).
So, in summary: You can derive pretty much nothing of value from these numbers.
I am betting that this is well placed pr, paid for by freelancer.com. I thought I saw an article on the exact same topic several months ago, also featuring freelancer.com.
They're also trying to extrapolate to the end of 2012 (17 months away!), and they're only counting freelancing jobs (which needs to be reflected in the title, OP).
So, in summary: You can derive pretty much nothing of value from these numbers.