SQL & PL/SQL

Hi, I'm having a little problem here.

I have a table that has one column for each month containing values that can be null. I need to get the year's average on a single row on a query level. I have made an extra column that stores the average but I wanted to know if it was possible to do it without adding the column to the table.

Here's an example of what I have

Year Jan Feb Mar .................................................................... Dec
1952 1.2 2.2 3.4 1.7
1953 1.4 2.5 2.7...................................................................... null

I need the AVG on each year... I'm lost right now, any help or information on this topic would be welcomed.

Thanks