Your URLs 1 and 2 seem broken. This a bug somewhere? Could you repost them please? Also on 3 and 4 the mean wage for Software Developer, Applications and Systems seem quite a bit higher than the other category you've highlighted (though Web dev is not so much).

On another note, I'm going to make myself sick reading about this stuff. I find that the reality is a bit of info is helpful for guidance, and too much is like tabloid journalism or sickly sweet candy.