In 2001, about 74% of Austria's population were registered as Roman Catholic, while about 5% considered themselves Protestants. Austrian Christians, both Catholic and Protestant, are obliged to pay a mandatory membership fee (calculated by income—about 1%) to their church; this payment is called "Kirchenbeitrag" ("Ecclesiastical/Church contribution"). Since the second half of the 20th century, the number of adherents and churchgoers has declined. Data for the end of 2016 from the Austrian Roman Catholic church lists 5,162,622 members, or 58.8% of the total Austrian population. Sunday church attendance was 605,828 or 7% of the total Austrian population in 2015. The Lutheran church also recorded a loss of 74,421 adherents between 2001 and 2016.