Is this business for sale?

As an entrepreneur who builds software, it would be nice to know some high-level data like: 1) What are the different sectors of the economy ranked by GDP? 2) To what degree has software penetrated those sectors? 3) What barriers exist in those sectors? 4) Are those sectors growing, shrinking, or staying the same?

Obviously, (1) is answered and I'm sure people have written about the other questions in an ad-hoc manner, but has anyone done a top-level data-driven analysis?

I was thinking about this after hearing people at Stripe talk about "growing the GDP of the internet." I think the GDP of the internet will grow at the expense of GDP not on the internet over the next few decades. This will have broad implications on the economy that should inform where we choose to build software products.

Any resources would be appreciated, even if they're only pieces of the puzzle.