What do Y axes mean in Sensitivity Analysis results?

Hi,

I have the following results in Sensitivity analysis toolbox, see attached figure.

I have specified step response envelope as follows: both for X and Y rise time is 0.15 s, settling time is 0.2 s, overshoot 5%. Final value of X is 0.31 and Y is -0.96.

I have generated 150 samples of 6 parameters that I want to check, and the results give me some information, of course, but I do not understand the Y axis values in all plots, why they are from 0 to 250? And what to these hystogramms to the right from scatter plots show? why are they both from 0 to 0.3?