After a brief and shallow dip late last year, New Brunswick resumed growing this year in what has developed into the longest and largest expansion of population in the province in nearly 30 years.

According to new Statistics Canada estimates released Wednesday, New Brunswick was home to a record 773,020 people on April 1, an increase of more than 4,000 from last April and up 14,082 over the last 16 quarters, or four years.

That's the largest sustained increase in population in New Brunswick since the province added just over 17,000 people between 1988 and 1992.

"There's still growth," said Statistics Canada demographer Francois Sergerie about New Brunswick's latest quarter, which reversed a small decline in population detected in late 2018.

"For the last five years in New Brunswick (20 quarters), only five quarters were negative," said Sergerie

Population growth is being driven almost exclusively by international immigrants arriving in New Brunswick, a critical need for a province that would be aging and shrinking rapidly without newcomers, according to several economists.

Last month. Fred Bergman of the Atlantic Provinces Economic Council told CBC News that attracting immigrants is important to the province but pointless unless they put down roots.

Immigrant retention is key to sustaining population growth, says Fred Bergman of the Atlantic Provinces Economic Council. Above, applicants check out a job fair for newcomers in Saint John last year. (Graham Thompson/CBC)

"The key is you hope to retain some of those people, especially the immigrants," Bergman said in an interview with Information Morning Fredericton.

"Keeping them here, making sure they settle here and are less likely to move to a larger urban centres in other parts of Canada outside the Maritimes."

Listen to the full Information Morning Fredericton interview with Fred Bergman

Figures show New Brunswick added 1,013 immigrants during the first three months of 2019, accounting for the province's entire population increase during that period. And while Syrian refugees were the dominant number of new arrivals three years ago, that has since switched over to people from Asian and Pacific countries such as the Philippines and China.

Progress is slow

The resumption of population growth is beginning to undo several years where New Brunswick's size stagnated — and even began shrinking — but progress is still slow.

The addition of 4,000 people in the last year grows the province by less than six-tenths of one percent, a rate that is ninth among the 10 provinces (behind only Newfoundland and Labrador) and one-third of the national growth rate.

That's partly because traditional internal sources of population growth no longer work as they once did.

New Brunswick's rate of population growth in the last year ranks ninth of the 10 provinces. (Joe MacDonald CBC News)

The birth rate in New Brunswick continues to plummet, with just 6,599 babies born in 2018, a modern low that was 972 fewer than the number of people who died.

That upside down birth/death exchange now saps population from New Brunswick every year, so that only immigrants have been preventing the serious demographic problems that hit the province a decade ago.

Between 1997 and 2007, New Brunswick's population stopped growing and then fell by more than 7,000 as large numbers of people moved west looking for work and immigrants were too few to make up the difference

Sergerie noted that is not happening again only because of the arrival of newcomers.

"International immigration is important for the country as a whole," Sergerie said. "In 2019, 80 percent of the growth was explained by international migration. New Brunswick is not different."