Ms Parata said the 2012 national aggregate data showed reported achievement against the National Standards for reading increased from 76.2% in 2011 to 77.4% in 2012; for mathematics, it increased from 72.2% to 73.6%; and for writing, it increased from 68% to 70%.
Pasifika children showed the greatest increase, improving by about 3% in all three standards.
However, the data also showed some concerning trends, including a decline in the rate of achievement as the year level increased, especially in mathematics, she said.
Although the latest data was in line with other studies, she said it showed disparity continued to exist in New Zealand's education system.
In particular, achievement was significantly lower for Maori and Pasifika learners, and boys trailed girls.
On top of existing support programmes to help pupils who fell below the National Standards, the ministry had established an advisory group with expertise in literacy and numeracy, and asked it to make recommendations about what could be done better to address these issues, she said.
The ministry also hoped to introduce the Progress and Consistency Tool (Pact) for National Standards and Te Waharoa Ararau for Nga Whanaketanga Rumaki Maori later this year, which would help teachers make reliable and consistent judgements.
''It's great to see that around 70% of children are at or above the National Standards, and the increase in Pasifika achievement.
''It's a credit to our teaching profession to see progress being made child by child and school by school.
Individual school data would be released later this month, she said.
Otago Primary Principals' Association president Whetu Cormick accused the Government of wasting millions of dollars on introducing irrelevant National Standards to produce data that told schools what they already knew.
''The minister may take comfort in her perceived valid data, but the inconsistent manner in which teacher judgements are made across the country brings into question the validity of this.
''Clearly, these standards are flawed by design, and any attempt to mandate Pact will not solve these inconsistencies.''
He said the data for Maori and Pacifika pupils was nothing new.
''We already know that Maori children are underachieving and the big challenge for the minister is what is going to be done to support these students.
''Removing programmes such as Te Kotahitanga needs to be reviewed.
''Perhaps also listening to the views of community and the people who know how to engage Maori kids, teachers, might be useful.''
New Zealand Educational Institute president Judith Nowotarski said the data was ''as unreliable and invalid as last year in terms of judging teacher or school effectiveness'', and parents would not find it reliable or useful to make judgements about either their own child or their local school.
The only conclusion that could be drawn was that there was a strong correlation between a child's socio-economic status and their educational achievement, she said.
