Listen, I don't believe that Greece is 98% Greek. I remember reading somewhere something about official statistics finding that 10% of the population of Greece do not hold Greek citizenship (i.e. are immigrants). Perhaps the 98% figure pertains to the remaining 90% which would be something like 88.2% of the total population. I think all this speculation qualifies as original research though. What is interesting is the question of "what are the Roma (Gypsies/Τσιγγάνοι)?" According to the Greek government again, they number about 200,000 - are they included in the ethnic Greeks figure? According to official statistics again (1991 census), the Thrace minority is 0.98% of the total population at that time (about 28.8% of the total population of Thace at that time). I think we should just stick with The World Factbook's estimate and avoid all the speculation.