People from the 10 newest EU countries accounted for more than 60 per cent of immigration into this State last year, figures from the Central Statistics Office show.
In each of 2002 and 2003, there were less than 10,000 arrivals from the accession states, according to data based on PPS allocation and employment statistics from the Department of Social and Family Affairs and the Revenue Commissioners.
But this rose to 59,000 in 2004 when the 10 accession states joined in May of that year. This accounted for 47 per cent of all foreign nationals migrating to Ireland.
In 2006, there were 139,000 arrivals from the accession states, accounting for 61 per cent of all arrivals.
A total of 67 per cent of this group were Polish, 12 per cent were Lithuanian, 8 per cent were Slovakian, 6 per cent were Latvian, and the remaining 7 per cent came from the other six states.
Of the migrants from the accession states, 42 per cent were aged 15-24, and another 43 per cent were aged 24-44, the CSO said. The ratio of males to females was 6:4 among migrants from the new states between 2004 and 2006.
The data shows a total of 118,000 foreign nationals aged 15 and over were assigned PPS numbers in 2004 but that only half of these had insurable employment in Ireland at any time during 2006.
Similarly, for the 2003 arrivals, 62 per cent had some employment in the year of PPS assignment, but this had fallen sharply to only 36 per cent by 2006.
The CSO warned against inferring that this reflected the movement of some migrants into the black market. It said the drop-off may be explained by those who returned home or are looking after households.