Count of clients at specific stage

The attached spreadsheet shows a simplified version of my problem.

I have many tabs, each that represents a different client (in the example they are the tabs called first, second, third), and they show what stage the client is currently at by indicating the date they went to that stage.

On the Stats tab I want to indicate how many clients are at each stage, in this case we have 1 client at stage 1.3 and 2 clients at 1.4.

Is there a simple way to do this for a lot of clients? Maybe my spreadsheet could be formatted in a different manner to make this simpler?

Many thanks