The US has ~316 Million people. 5% have a net worth of 1M or more. ~20% are below the poverty line w no assets and less than 28k annual income, 1.2% live on less than $2 per day. 20% are working poor (no assets), 40% are working/middle class and 15% are upper middle class.
So you have 20% (rich and upper middle class) that have a quality education or personal drive aka self educated. Let's add in 10% to account for the top of the middle class, educated but lacking in opportunity or ambition or just not there yet.
30% of 300 Million, so 100 Million people with a 16 Million buffer. Let's take out the children and elderly, so we're left with 60% of that number (under 20 is ~28% and over 85 is ~12%) or 60 Million.
Unemployment is at 7.5% so we're at 45 Million.
I can't find a good source of jobs by industry at the moment (should be on bureau of labor site somewhere), so I'll just throw out 10% as a rough percentage of people who might be involved in something technical or scientific where they could be innovative in some way.
4.5 Million. Let's cut that in half to 2.25 Million for no good reason and then let's take 2% of that = 45k. That's 45 thousand people who could be starting up the next Apple, Google, etc. It really only takes a few people at the top to provide leadership.
What's my point? I don't know, but whatever it was I showed my work.