The last census in Austria that collected data on religion was in 2001. That census found that there were 338,988 Muslims in the country, making up 4.2% of the population. Statistics Austria estimated in 2009 that 515,914 Muslims lived in Austria.[26] Work by Ednan Aslan and Erol Yıldız that used data from the 2009 Statistics Austria report estimated that 573,876 Muslims lived in Austria in 2012, making up 6.8% of the population.[27]