WELLINGTON (BLOOMBERG) - New Zealand's population provisionally reached five million in March, aided by surging immigration in recent years, the nation's statistics agency said.

The South Pacific nation added one million people in the past 17 years, the fastest rate in its history, Statistics New Zealand said in an emailed statement Monday (May 18) in Wellington. The population rose by half a million since 2013, growing at an average annual rate of 1.8 per cent, it said.

"International migration played a significant role in reaching the five million milestone," population insights senior manager Brooke Theyers said in the statement. "About half of the population growth from four to five million was due to natural increase, and about half from net migration."

Other countries with populations of between five and six million include Costa Rica, Denmark, Finland, Norway, Singapore, and the Slovak Republic.

More than one million people born overseas now live in New Zealand, while hundreds of thousands of New Zealand-born people live overseas, especially in Australia, Theyers said.

She said the global coronavirus pandemic has boosted net immigration in recent months, with more New Zealand citizens returning home after living overseas and fewer citizens able or willing to head offshore.

The estimated resident population was provisionally 5,002,100 at March 31. It increased by 96,800 from March last year, of which 71,500 was net immigration. The data are subject to revision.