According to the 2011 census, the total population of the five counties of Slavonia was 806,192, accounting for 19% of population of Croatia. The largest portion of the total population of Slavonia lives in Osijek-Baranja county, followed by Vukovar-Syrmia county. Požega-Slavonia county is the least populous county of Slavonia. Overall the population density stands at 64.2 persons per square kilometre. The population density ranges from 77.6 to 40.9 persons per square kilometre, with the highest density recorded in Brod-Posavina county and the lowest in Virovitica-Podravina county. Osijek is the largest city in Slavonia, followed by Slavonski Brod, Vinkovci and Vukovar. Other cities in Slavonia have populations below 20,000. According to the 2001 census, Croats account for 85.6 percent of population of Slavonia, and the most significant ethnic minorities are Serbs and Hungarians, comprising 8.8 percent and 1.4 percent of the population respectively. The largest portion of the Serb minority was recorded in Vukovar-Syrmia county (15 percent), while the largest Hungarian minority, in both relative and absolute terms, was observed in Osijek-Baranja county. The census recorded 85.4% of the population declaring themselves as Catholic, with further 4.4% belonging to Serbian Orthodox Church and 0.7% Muslims. 3.1% declared themselves as non-religious, agnostics or declined to declare their religion. The most widely used language in the region is Croatian, declared as the first language by 93.6% of the total population, followed by Serbian (2.6%) and Hungarian (1.0%).