The figures showed 45,060 travellers arrived for long-term or permanent stays in Australia in June, while there were 28,700 long-term or permanent departures.
In other words, there was a net inflow of 16,360.
In June last year, the net inflow was 19,400, and in June 2013 it was 27,180. Annual totals show the same declining pattern.
Over the year to June, the net inflow was 292,300, compared with 356,400 in the year to June 2014, and 407,100 in the 12 months before that.
The passenger travel figures from the Australian Bureau of Statistics are based on the intentions of the travellers as they arrive, not on what they end up actually doing.
And fluctuations in immigration are the major reason for changes in population growth from year to year.
Changes in birth and death rates are not as important, because they occur more gradually over time.
That the RBA devoted a special section to population in its quarterly Statement on Monetary Policy appears to reflect the concern aired by the central bank's governor, Glenn Stevens, that slow population growth may have reduced the economy's potential growth rate.
"Lower population growth has important implications for the economy," the RBA said in the quarterly statement.
It lowers demand for goods and services from what it otherwise would have been, as well as the economy's capacity to supply them.
But the implications for variables like the unemployment rate depend on the strength of the supply and demand effects.
"For example, over the past year or so, lower population growth may help to explain why the unemployment rate has stabilised despite below-average growth in GDP."
The RBA's analysis showed much of the slowdown in immigration has been in the age group denoted as "prime working age", from 25 to 44.
Strong labour demand in New Zealand owing to the reconstruction of earthquake-damaged Christchurch may be part of the reason for that, the RBA suggested in the statement.
If the economy's potential growth rate has stepped down, that would imply the RBA has less need to boost the economy by cutting interest rates.
It also suggests the ABS measure of employment growth may be overstated.
While net traveller inflows have slowed markedly, the bureau's assumption for working-age population growth, used as the basis for the monthly jobs figures, has not slowed at all.

Source: NZ Herald