How many Ulthera shots do I need to see results?

I think my skin thickness is above average,

The elasticity on the other side looks fine,

My jaw area is a bit sagging compared to my entire face.

And I think my face is a bit wide haha.

I'm in my late 30s; given these conditions, how many shots should I take?

I think it needs to be over 300, but I am also curious if there is an upper limit.