Why only American Korean get ped the SM Global Audition ?

Annually, SME holds the Global Audition to recruit the trainees from other countries in Asia. And as I can see, only American Korean get ped those audition such as Jessica (SNSD), Krystal & Amber [f(x)], ... Sometimes there're some Chinese as well like HanGeng (Super Junior), Victoria & Amber [f(x)], ... But WHY THERE AIN'T ANY SM's TRAINEE HAVE OTHER CITIZENSHIP like Malaysian, Indonesian, ... ??? Is there some unfair judging criterion for those citizen ???