I have used the following code to generate two seperate graphs. How do I combine the two graphs onto one by generating a 2nd Y-Axis as I'd like to show the relationship of the two line graphs together?

egen meanCEOTotalCompensation = mean(CEOTotalCompensation), by(Year)
egen meanShareholderReturn = mean(ShareholderReturn), by(Year)
egen tag = tag(Year)
twoway connected meanCEOTotalCompensation Year if tag, sort
twoway connected meanShareholderReturn Year if tag, sort

Any help would be greatly appreciated!