How to Sum the Max values in a Pivot

Hello all, I'm hoping someone will be able to give me a hand with this.

I'm trying to get the Sum of the Max values in a Pivot, the problem is the underlying data, and thus the Pivot, will be frequently updated and a variable size so I can't just select a specific range to Sum.

My example has a very small chunk of what the data looks like, and the pivot I put together that gets me as close as I can to the result I want.

The solution I'd be looking for would look like the highlighted cells in N, which from there I can calculate the number of order lines a user picks in an hour.

I'm open to any kind of solution, the data is just copy/pasted in from another source so it can be manipulated if need be.

Appreciate any help!

If you really sum each instance of the same time you will different numbers than what you pointed.
I created a new column in the PT to sum, but it sum it all, including the equal time.

That's perfect, thank you! Simple and efficient. I've never used Power Pivot before, definitely going to try it out going forward.

Cheers!