Demographics of Iraq
97% of Iraqis follow Islam: 61% Shia and 34% Sunni. 1% of these describe themselves as "Just a Muslim". According to the CIA Factbook, Shias make up 60% of population, while Sunnis 35%. Christianity accounts for 5%, and the rest practice Mandaeism, Yazidism and other religions.
Ahwazi Arabs
According to Library of Congress, Iranian Arabs constitute 1-2% of Iranian population. The majority are Shia Muslims, while a minority, concentrated in the coastal areas, are Sunni Muslims.