Huge gaps between boys and girls, and among New Zealand's main ethnic groups, show no sign of closing in the latest data on primary school literacy and numeracy.
Boys have dropped further behind girls in both reading and writing in the data on the numbers reaching national standards for their year level.
The gap is widest in writing, where the proportion of girls achieving the standards was unchanged at 79.4 per cent, but boys reaching the standard fell slightly from 63.9 per cent in 2015 to 63.4 per cent in 2016.
The 16 per cent gap between girls and boys in writing is now wider than it has ever been since national standards were introduced in 2010.
However, boys have almost caught up with girls in mathematics, climbing from 74.8 per cent achieving standard in 2015 to 75 per cent last year, a slither behind girls on 75.9 per cent.
Overall the data shows very slight declines in the numbers of all primary and intermediate students achieving all three standards: down from 78 per cent in 2015 to 77.8 per cent in reading, from 71.4 per cent to 71.2 per cent in writing, and from 75.5 per cent to 75.4 per cent in maths.
Achievement rates in all three subjects are still well below a target, fixed by former Education Minister Hekia Parata in 2013, of 85 per cent of students achieving the standards by 2017.
The target was re-set in May this year at 80 per cent of Year 8 students achieving the standards in writing and maths by 2021.
Source: Ministry of Education
The latest data shows that only 69.2 per cent of Year 8 students achieved the standards in writing, and 70.3 per cent in maths.
Year 8 achievement in both subjects was up slightly from 2015, but the data has varied considerably over the years.
National standards judgments are still believed to be unreliable between schools because they are based on "overall teacher judgments" of each student's performance, rather than standardised tests.
However, the gender and ethnic gaps may be more reliable because each school can be expected to apply the same judgments to all its students regardless of their gender or ethnicity.
Education Minister Nikki Kaye said the standards had proved "an invaluable mechanism for targeting extra help to children who need it".
"But too many of our students are still not achieving in the key areas of maths and writing, the two core skills that open up a world of possibilities right across the curriculum," she said.
"The data also tells us that achievement levels in those subjects are decreasing between Years 4 and 8."
However, Professor Martin Thrupp, who has written a new book on national standards, has pointed out that the Year 8 maths standard was deliberately set above the average achievement levels of Year 8 students because of a perceived need to lift achievement levels.
Kaye issued an 11-page Result Action Plan to achieve the new 80 per cent target for Year 8 students in writing and maths by 2021.
Ethnically, the data show a slight narrowing of the gap between European and Pasifika students from 19.7 percentage points in 2013 to 18.2 points in 2016 in reading, from 18.7 to 16.6 points in writing, and from 18.9 to 18.1 points in maths.
But the gap between European and Māori students has been unchanged at between 15.2 and 15.7 points in every subject in every year since 2013.