differ from community to community. Zoroastrian prayers, called , are conducted usually with hands outstretched in imitation of Zoroaster's prayer style described in the Gathas and are of a reflectionary and supplicant nature believed to be endowed with the ability to banish evil. Devout Zoroastrians are known to cover their heads during prayer, either with traditional topi, scarves, other headwear, or even just their hands. However, full coverage and veiling which is traditional in Islamic practice is not a part of Zoroastrianism and Zoroastrian women in Iran wear their head coverings displaying hair and their faces to defy mandates by the Islamic Republic of Iran. Demographics Zoroastrian communities internationally tend to comprise mostly two main groups of people: Indian Parsis and Iranian Zoroastrians. According to a study in 2012 by the Federation of Zoroastrian Associations of North America, the number of Zoroastrians worldwide was estimated to be between 111,691 and 121,962. The number is imprecise because of diverging counts in Iran. Iran and Central Asia Iran's figures of Zoroastrians have ranged widely; the last census (1974) before the revolution of 1979 revealed 21,400 Zoroastrians. Some 10,000 adherents remain in the Central Asian regions that were once considered the traditional stronghold of Zoroastrianism, i.e., Bactria (see also Balkh), which is in Northern Afghanistan; Sogdiana; Margiana; and other areas close to Zoroaster's homeland. In Iran, emigration, out-marriage and low birth rates are likewise leading to a decline in the Zoroastrian population. Zoroastrian groups in Iran say their number is approximately 60,000. According to the Iranian census data from 2011 the number of Zoroastrians in Iran was 25,271. Communities exist in Tehran, as well as in Yazd, Kerman and Kermanshah, where many still speak an Iranian language distinct from the usual Persian. They call their language Dari (not to be confused with the Dari of Afghanistan). Their language is also called Gavri or Behdini, literally "of the Good Religion". Sometimes their language is named for the cities in which it is spoken, such as Yazdi or Kermani. Iranian Zoroastrians were historically called Gabrs, originally without a pejorative connotation but in the present-day derogatorily applied to all non-Muslims. The number of Kurdish Zoroastrians, along with those of non-ethnic converts, has been estimated differently. The Zoroastrian Representative of the Kurdistan Regional Government in Iraq has claimed that as many as 100,000 people in Iraqi Kurdistan have converted to Zoroastrianism recently, with community leaders repeating this