Religious groups and nonreligion
Survey data from the Barómetro of the Centro de Investigaciones Sociológicas shows a sharp increase in those who consider themselves nonreligious in the last 20 years. Whereas in 2003 15,5% of the respondents considered themselves nonbelievers or atheist, the figure of those who defined themselves as agnostic, nonbeliever or atheist raised to 41,7% in 2023. In parallel, those who identified as Catholic declined from 81% to 53,9% in the same period.