Non-Irish nationals now account for 5.8 per cent of residents in the State and the population of Muslims and Orthodox adherents has increased sharply, a breakdown of last year's Census shows.
The findings of the 2002 Census published today gives the breakdown of the Ireland's population of 3,917,203 by age, sex, martial status, household composition, usual residence, nationality and place of birth as well as information on the Irish language, religion and Irish Travellers.
The number of Muslims more than quadrupled to 19,000 since the 1991 Census; the number of Orthodox adherents increased from less than 400 in 1991 to over 10,000 in 2002. Both categories have been clearly affected by immigration flows, the Central Statistics Office said.
The long-term decline in the numbers recorded as Church of Ireland, Presbyterian and Methodist adherents has reversed. Immigration is also likely to have exerted a major influence on these trends.
The number of Church of Ireland members has risen from 89,200 in 1991 to 115,600 in 2002; immigrants comprise 19,000 of that increase.
The percentage of Roman Catholic adherents declined from 91.6 per cent in 1991 to 88.4 per cent in 2002.
The State's population has aged by a year since 1996 leading to an average age of 35.1 years in 2002 compared with 34.1 six years earlier. As a consequence of the population getting older, people aged 65 or more living alone comprised 41 per cent (or 113,800) of all people living alone in 2002. People aged 75 or more accounted for 21.5 per cent (or 59,800) of the total.
The Census also reveals the number of divorced persons more than trebled, from 9,800 to 35,100, between 1996 and 2002, largely reflecting the legalisation of divorce in the State in 1997.
The number of separated (including divorced) persons increased from 87,800 in 1996 to 133,800 in 2002. Couples living together accounted for 8.4 per cent of all family units in 2002 compared with 3.9 per cent six years earlier.
The Census report also shows that the number of women in April 2002's total population exceeded the number of men by about 25,000. The population has increased by 291,116 or 8 per cent since April 1996.
Leinster is the most populous province, with two million residents. Its share of the overall population of the State has increased in every census since 1926 while the shares of the other three provinces have declined during the same period.
Six out of every ten persons lived in urban areas in 2002, compared with less than one in three at the time of the foundation of the State.
According to a new question introduced in the 2002 Census, there were nearly 24,000 Travellers counted in April 2002. The Traveller Community has a very distinctive age structure resulting in a median age of 18 years compared with a national figure of 32 years.
The proportion of young Travellers aged 0-14 years was twice as high as the corresponding rate for the State as a whole.