Ethnic groups: Arab 40%, Pakistani 18%, Indian 18%, Iranian 10%, other 14%

Source:
http://en.wikipedia.org/wiki/Demographics_of_Qatar

Can anyone explain why "Arab" and "Iranian" are separate categories?

"In July 2007, the country had a growing population of approximately 907,229 people (1.4 million in May 2008), of whom approximately 350,000 were believed to be citizens. The majority of the estimated 800,000 non-citizens are individuals from South and South East Asian and Arab countries working on temporary employment contracts in most cases without their accompanying family members."

I copied this from Wikipedia following a search for "Qatar".... http://en.wikipedia.org/wiki/Qatar#Population