By David Hargreaves

Non-New Zealanders are continuing to depart the country in big numbers, which is causing the net gain from migration to fall quite quickly from high levels.

Over 2600 non-New Zealanders left the country in April, which was the highest total for an April month since Statistics New Zealand started publishing this information in 1978.

In the year to April, more than 30,000 non-New Zealanders left the country, which is up some 23% on the figure a year earlier.

The overall monthly gain from migration in April was 2460, which is the lowest monthly increase since May 2014.

The net migration gain in the year to April was 67,038, according to Statistics New Zealand.

That's down from record levels of over 72,000 seen during last year and is the lowest annual gain in around two years.

The figures are of course seasonal, but the trend for slowing migration growth is also demonstrated by Stats NZ's seasonally-adjusted figures, which 'smooth' out seasonal variations in migration patterns.

The seasonally-adjusted migration gain in April dipped below 5000 for the second time in three months.

You have to go back to the end of 2014 for the last time that happened.

If you take the average seasonally-adjusted gain across the past three months, and annualise it, this gives an annualised gain of around 61,000 net migrants - which is still high historically, but well off the kind of pace being set a year ago.

Stats NZ said the gain for the April 2018 year was made up of 130,500 migrant arrivals and 63,400 migrant departures.

“Interestingly, the number of arrivals increased in the April 2018 year, so it is the larger increase in departures that drove the lower net migration level,” population insights senior manager Brooke Theyers said.

More than 98,000 non-New Zealand citizens arrived in the April 2018 year. However, more than 30,000 non-New Zealand citizens left this country over the same period, up 23% on a year earlier.

This resulted in a net migration gain of non-New Zealand citizens of 68,100.

Conversely, the net migration from New Zealand citizens was a loss of 1,100 – made up of 32,100 arriving and 33,200 departing.

In the April 2018 year, migrant arrivals on work visas rose 5% to 46,400, while there was a 14% fall in arrivals on residence visas, compared with a year ago.

"The number of migrants coming to New Zealand to work has been generally increasing since the September 2010 year, and work visas have become the largest visa type from the March 2015 year," Theyers said.

"Migrant arrivals of New Zealand and Australian citizens have also been increasing since September 2012, but this increase has not kept pace with the increase in work visas."

The countries that were the biggest sources of work-visa migrants were the United Kingdom, France, and Germany.

A residence visa allows migrants to live in New Zealand permanently. There were 14,300 arrivals on residence visas in the April 2018 year, down from 16,700 in the April 2017 year.

The source countries with the largest decreases in residence-visa migrants to New Zealand for the April 2018 year were:

China (2,800 – down 700)

United Kingdom (900 – down 500)

India (900 – down 400)

Philippines (700 – down 300).

The number of student-visa migrants stayed almost the same in the April 2018 year (down 100, to 23,700), while the number of New Zealand and Australian citizen migrants increased (up 600, to 38,700).