Welcome to PF;
If you are starting your studies now or shortly, you are asking the wrong question.
What you need to do is figure out which is likely to be growing in such a way that by the time you graduate (3-5years) you are likely to be employed in the field.
Todays growth tells you nothing by itself.
It is also a bad way to pick a career path, since it leaves so much unconsidered, but that's your business right?