Problem with rampTo results

[ghost]

How does rampTo really work, since when I run the script several times it gives me different results, what I see is that the number of scenarios launched changes.

Is there a formula or operation to see why the scenarios were created?

This is my phase

• duration: 5
  arrivalRate: 4
  rampTo: 10
  name: "Phase1"

Evidence

These results were taken from the same tests of the script with the phase above added

I ask for your help please as I am very confused by this random scenario data that shows me the result