Most likely people will tell you this is your hardware issue/limit.
I myself have all my games framerate drop when i hit around 13 colonist and gets progressively worse until i hit around 20+ which the game game starts stuttering to the point that i can't continue playing it.
I myself have all my games framerate drop when i hit around 13 colonist and gets progressively worse until i hit around 20+ which the game game starts stuttering to the point that i can't continue playing it.