While population estimates in Azerbaijan are considered reliable due to regular censuses, the figures for Iran remain questionable. Since the early twentieth century, successive Iranian governments have avoided publishing statistics on ethnic groups. Unofficial population estimates of Azerbaijanis in Iran are around the 16% area put forth by the CIA and Library of Congress. An independent poll in 2009 placed the figure at around 20–22%. Nevertheless, regardless of the highest or lowest estimates or publications, Azerbaijanis in Iran comprise by far the second-largest ethnic group in the nation as well as by far the largest minority ethnic group. Furthermore, once again regardless of any estimate or publication, the number of Azerbaijanis in Iran by far outnumber the amount of Azerbaijanis in the neighboring Republic of Azerbaijan, and comprise the largest number of ethnic Azerbaijanis in the world.