Scotland a territorial parish structure, with every community in Scotland having a local congregation. Scotland also has a significant Roman Catholic population, 19% professing that faith, particularly in Greater Glasgow and the north-west. After the Reformation, Roman Catholicism in Scotland continued in the Highlands and some western islands like Uist and Barra, and it was strengthened during the 19th century by immigration from Ireland. Other Christian denominations in Scotland include the Free Church of Scotland, and various other Presbyterian offshoots. Scotland's third largest church is the Scottish Episcopal Church. Islam is the largest non-Christian religion (estimated at around 75,000, which is
Demography of Scotland It has been suggested that they would have had a mean population of about 2,000, but many would be much smaller than 1,000 and the largest, Edinburgh, probably had a population of over 10,000 by the end of the era. Calculations based on Hearth Tax returns for 1691 indicate a population of 1,234,575, but this figure may have been seriously affected by the famines of the 1690s. The first reliable information is a census conducted by the Reverend Alexander Webster in 1755, which shows the inhabitants of Scotland as 1,265,380. By the time of the first decadal census in 1801,