How do you know that all pilots who train with SAA stay in Sweden? How are you in a position to know any Swedish pilots who've left the country and work abroad. There are some believe me
You're talking about 50 year old pilots who would have qualified nearly 30 years ago. The aviation world was a very different place 30 years ago; no JAA, only national licences which may not have been recognised abroad.
Up until recently, Sweden was not part of the EU and therefore there was no automatic right to work in other countries. Therefore, these older pilots may not have been able to work elsewhere in the world and they didn't have the appropriate visas.
Also bear in mind that many people actually want to stay in their own country, they have family there, maybe married and have children and no wish to uproot to move elsewhere.
You seem to have this idea that the major airlines simply to to OAA at graduation time and just take all the recruits; they don't. Also bear in mind, that OAA has a lot of foreign sponsored students who are pretty much guaranteed jobs in their own country - they use these students in their statistics as well which will skew the percentages.
Cheers
Whirls