The country has an area of 27,136 square miles and a population of 4.3 million. According to the 2006 census, the religious affiliation of the population is 86.8 percent Catholic, 2.9 percent Church of Ireland, 0.76 percent Muslim, 0.68 percent unspecified Christian, 0.55 percent Presbyterian, 0.49 percent Orthodox, 0.28 percent Methodist, less than 0.1 percent Jewish, and 6 percent unaffiliated.
An estimated 84,000 immigrants arrived in the country during the reporting period; almost half of these immigrants came from other European Union states. Muslim and Orthodox Christian communities in particular continued to grow, especially in Dublin.
According to 2005 figures released by the Catholic Communications Office (CCO), approximately 60 percent of Catholics (including those in Northern Ireland) attend Mass once a week and 5 percent attend Mass once a day. The CCO reported a noticeable increase in attendance during Easter and Christmas holidays. In part because many priests are close to retirement, the Irish Catholic press predicted that the percentage of Catholics attending Mass regularly would decline in coming years. A similar survey conducted in 2005 by the Evangelical Alliance Ireland estimated that up to 30,000 evangelicals (comprising Baptists, members of Assemblies of God, Pentecostals, and charismatics) attend services each week.