SQL & PL/SQL

I'm trying to work out how to select the year and month number, of all months for the last 5 years. I want this so I can left join in some data but have all of the gaps filled.

ie..

Year      Month

2014      1

2014      2

2014      3

....

2013     1

2013     2

....

I can get the last 5 years using something like this:

select extract(year from sysdate) -level year
from dual
connect by level <= 5

But I'm not having much look adding to this to get all of the months aswell. Can anyone help?

Thanks!