The entrepreneurial rate in most countries had nowhere to go _but_ up, so this really tells us nothing more than the fact that a lot of countries have woken up and reduced the structural disincentives to entrepreneurship that had been in place. It is also not possible at this time for a country to be 100% entrepreneurs (or even close to that) and every additional percentage of entrepreneurship takes more and more effort.

Corporate taxes, beyond the obviously bad levels you see at the extremes, are not as directly tied to either entrepreneurship nor unemployment rates as you would suggest (c.f. in the late 90s we had higher taxes and much lower unemployment numbers -- the reason why this was the case is easy to see in retrospect, but it is a simple and direct example of how your arguments are flawed.)