There is something off with these numbers, especially the UK figures. $43000 average for a software developer would be about £26500, thats quite low. I would expect it to be in the mid £30Ks.
[1] - http://targetjobs.co.uk/career-sectors/it-and-technology/286...
It's entirely dependant on the language involved though. Ruby/Python/iOS developers for example, earn £45k on average.