According to the 2015 census, 92.9% of all Polish citizens adhere to the Roman Catholic Church. An estimated 94.2% of the population are believers and 3.1% are irreligious, making Poland one of the more devout countries in Europe. Around 61.6% of all respondents outlined that religion is of high or very high importance. However, church attendance has decreased in recent years; only 38% of worshippers attended mass regularly on Sunday in 2018. Freedom of religion is guaranteed by the Polish Constitution, and the concordat guarantees the teaching of religion in state schools.