 A study carried out on behalf of the British Humanist Association at the same time as the 2011 census suggested that those not identifying with a denomination, or who see themselves as non-religious, may be much higher at between 42 and 56 per cent, depending on the form of the question asked.In 2016 the Scottish Social Attitudes survey found that 52 per cent of people said they are not religious, compared with 40 per cent in 1999 when the survey began.While Roman Catholic (15 per cent) and other Christian (11 per cent) affiliations have remained steady, the decline is most rapid in the Church of Scotland, from 35 per cent in 1999 to 20 per cent.