Hello!

I have three parameters that measure an examiners performance over time. The data is noted for around 10 examiners and is decreases over time, indicating better performance - I already performed analysis with linear mixed model analysis and more.
Now I want to generate a graph plotting the values over time with the following code:

Code:
tsset Examiner IndexNumberOfExamination
twoway (tsline PerformanceValue1) (tsline PerformanceValue2) (tsline PerformanceValue3) if IndexNumberOfExamination < 50, by(Examiner)
This already gives me a nice graphical overview but as the performance values are fluctuating a bit, I would like to add a regression or trend-line to visualize decrease. Anyone got an idea how to do that?

Thanks a lot!
Michael