[Marcos Almeida]

With regards to your question in #13, i.e., how to put it in table and get summary information, you may type something like:

tabulate catvar, sum(numvar)
tabulate catvar1 catvar2, sum(numvar)

[Tonni Xia]

What you're asking for isn't possible. In your example data, sometimes the F_2005 and F_2006 scores are different, whereas your proposed result contains a single value that is supposed to represent both variables. In order to do something like this, you have to create a new variable, and it must be created in a way that somehow resolves discrepancies between F_2005 and F_2006 when the two are different.

thanks Clyde,
I think you are right. I need to think about it again.

Have a great weekend.

Tonni