Estimates for the size of the “Irish diaspora” vary hugely, from three million to 70 million depending on who is talking.

It also depends on what definitions they use for what constitutes the “diaspora”: whether it be people abroad with an Irish passport, an Irish-born granny, or those who claim any Irish ancestry at all, no matter how distant.

Such arguments will no doubt rumble on. However, thanks to a United Nations international migration report, which collated population data provided to them by 72 countries worldwide in 2013, we now have a fairly good understanding of the size of one section of the country's elusive diaspora: the Irish-born population living in these countries.

[ interactive global map showing where Irish emigrants live hereOpens in new window ]

More than three quarters of a million (771,572) people born in Ireland were reported to be living in these 72 countries in 2013, an increase of almost 5 per cent on the 2010 figure due to a rise in post-recession emigration out of Ireland.

However, the 2013 figure was 155,476 less than the number of Irish living in these locations in 1990, just after the height of the last wave of economically-driven mass emigration from Ireland.

The number of people born in the Republic living in the UK and Northern Ireland fell by one-third between 1990 and 2010, before rising 3.6 per cent to 412,658 in 2013.

Similarly, the Irish-born population in the US fell by 29 per cent between 1990 and 2010, before witnessing a 3.6 per cent increase to 143,571 in 2013.

In contrast, the Irish-born population in Australia, the most popular destination for recent Irish emigrants after the UK, jumped by 43 per cent between 1990 and 2013, from 54,318 to 77,513.

Compensating somewhat for the drop in the numbers of Irish in the UK and US is the exponential growth of Irish populations in countries across Europe.

The most popular European destination outside the UK for Irish expats is Spain, with 17,519 living there in 2013, up from just 2,065 in 1990.

A total of 9,664 Irish lived in France in 2013, up 44 per cent since 1990, while Irish populations in Austria, Belgium, Denmark, Finland, Luxembourg, the Netherlands, Norway, Portugal, Sweden and Switzerland have all increased by at least one-third, and up to five-fold in some cases.

The number of Irish in Germany has remained fairly consistent at about 12,000 since 1990.

Bucking the trend

Bucking the trend are Italy, where the Irish population has fallen by 5 per cent to 3,917, and Greece, where numbers have more than halved to 317 in the same time period.

Meanwhile, countries which joined the EU after 2004 have seen their Irish populations soar.

Hungary, for example, had just 26 Irish-born people in 1990, rising to 874 by 2013, while Latvia’s Irish population increased from 14 to 790 in the same period, and Lithuania’s from 18 to 934.

Perhaps the most remarkable growth is in Poland, where there are now 8,136 Irish-born people living, compared with just 101 in 1990.

The country with the smallest Irish population discovered by the UN report was St Helena, a British-owned island off the coast of South Africa, which has just two Irish residents. The Faroe Islands have just three, while the Falkland Islands and St Kitts both have six each.

Unfortunately, the UN report excludes countries which did not provide it with data on the number of Irish-born people living there, but in most instances, the Irish population in these countries is not likely to be significant, a UN spokesman told The Irish Times.

However, for countries where data was not provided but which are known to have a significant Irish population, The Irish Times requested figures from the Department of Foreign Affairs for citizens registered with their nearest Irish embassy.

This includes 7,000 registered as living in the United Arab Emirates; 3,000 in Saudi Arabia; 2,000 in Israel; 1,800 in China; 1,200 in Zimbabwe and 973 in the Republic of Korea.

While registration is voluntary, these figures give an approximate estimate in the absence of official census data.

Globally, more people than ever are living outside the country in which they were born, according to the UN report. In 2013, 232 million people, or 3.2 per cent of the world’s population, were international migrants, up from 175 million in 2000 and 154 million in 1990.