 Large @-@ scale emigration marked most of the post @-@ WWII period ( particularly during the 1950s and 1980s ) , but beginning in 1987 the economy improved , and the 1990s saw the beginning of substantial economic growth . This period of growth became known as the Celtic Tiger . The Republic 's real GDP grew by an average of 9 @.@ 6 % per annum between 1995 and 1999 , in which year the Republic joined the euro . In 2000 , it was the sixth @-@ richest country in the world in terms of GDP per capita . 
