Thank you for your information. Actually i did simulation following a manual of Monte Carlo simulation of Opamp,so i used gain but a switch do not provide gain. I will do the simulation again but need to know what does these figures mean.
Histogram statistics.
1. (HISTO) most results (Y Values) in the interval -480 .. -478m X Values
2. (CDF) 100% cumulative yield in the interval -492 .. -468m
3. (PDF) max. Y Value @ -479m X value. Σ values determinable from this curve
Whatever these X & Y values mean, you should know.