As with the spoken languages, the ethnic group composition also remains a point of debate, mainly regarding the largest and second largest ethnic groups, the Persians and <answer>Azerbaijanis</answer>, due to the lack of Iranian state censuses based on ethnicity. The CIA's World Factbook has estimated that around 79% of the population of Iran are a diverse Indo-European ethno-linguistic group that comprise the speakers of Iranian languages, with Persians constituting 53% of the population, Gilaks and Mazanderanis 7%, Kurds 10%, Lurs 6%, and Balochs 2%. Peoples of the other ethnicities in Iran make up the remaining 22%, with <answer>Azerbaijanis</answer> constituting 16%, Arabs 2%, Turkmens and Turkic tribes 2%, and others 2% (such as Armenians, Talysh, Georgians, Circassians, Assyrians).
What is Iran's presumed 2nd largest ethnic group?
Azerbaijanis