What FPS Are You Getting?

And any tips for potentially improving it?

I'm currently getting about 45 FPS with ~115 dwarfs. (limited to 150 max)

My world world was generated with 250 years history and has 1 fort that I retired after 6 years or so. 4x4 embark.

45 FPS is fine to play but it drops quickly after too many more dwarfs rock up.