How many drivers does Uber have

This post title comes from Google search. I wanted to know how many other Uber drivers are in the US and Google right away returned with this heading. So, I am not the first person who wants to know that.

Here are Google results:

Forbes: The Numbers Behind Uber's Exploding Driver Force

Uber’s active driver base has grown from basically zero in mid-2012 to over 160,000 at the end of 2014.