He said schools, and adults generally, were responsible for the environments that produced these figures.
"If I was a school principal, I would be horrified. I would feel like I've failed," he said. "I would be talking to other principals and saying, 'We have failed as principals if young people, especially young people who are marginalised because of their difference, are not feeling safe."
After the Wanganui case in March last year, Prime Minister John Key called for a "national conversation" about how to reduce bullying. The then Education Minister, Anne Tolley, wrote to school boards reminding them of their responsibilities to keep their schools safe.
A major report by Mr Key's chief science adviser, Sir Peter Gluckman, in May recommended more mental health support for children and adolescents.
Last month Mr Key unveiled an extra $62 million over four years for youth mental health projects, including more school nurses and youth workers, and asking the Education Review Office to create new indicators of student wellbeing such as the level of bullying.
The Ministry of Education's newly launched website, wellbeingatschool.org.nz, provides sample surveys for schools to use to find out whether students know what to do when bullying happens, although the samples do not ask students directly whether they have been bullied or for the bullies' names.
Some schools do ask students those direct questions, and try to help the bullies to change and supervise them closely until they stop bullying. But many schools don't ask.
The new Chief Human Rights Commissioner, David Rutherford, led a group of parents who complained to the Ombudsman about the handling of a horrific spate of bullying at Wellington's Hutt Valley High School in 2007 and said the first step towards tackling the problem was measuring it.
He said a 2009 official survey estimated that adults aged 15 and over were assaulted 699,000 times in the previous year, but children under 15 were not surveyed.
"It would be surprising if there were 700,000 assaults against people over 15 and none under 15."
A NATION OF BULLIES
A 2007 study of 9-year-olds in 35 countries found that 75 per cent of New Zealand students had suffered at least one of five forms of bullying in the previous month, higher than all other countries except Tunisia.
The five forms were being hit or hurt, having something stolen, being made fun of or called names, being made to do things they didn't want to do, and being left out of activities.
A third of Kiwi kids (33 per cent) suffered at least three of the five.
And an Auckland University Youth 2007 survey of 9100 pupils at 96 Kiwi secondary schools found 48 per cent had had false rumours spread about them in the past year, 41 per cent had been called hurtful names, 37 per cent had things taken from them and 35 per cent were physically hurt.
Bullying declined slightly since a previous survey in 2001. Students who felt safe at school increased from 78.1 per cent to 83.5 per cent, and those who were bullied at least once a week fell from 7.1 per cent to 6.1 per cent.
But one out of every class of 25 students (4.1 per cent) did not go to school at least once in the past month because of bullying.
A fifth (21.5 per cent) of the girls who were bullied, and 8.8 per cent of the boys who were bullied, attempted suicide in the past year.
THE DEFINITION
Bullying is defined by the Children's Commissioner's office as "deliberately harmful behaviour, repeated over a period of time, by a person or group who target a less-powerful person as the victim".
It can be physical, verbal or "relational", for example, excluding someone from a group.
In the Youth 2007 survey, 5 per cent of secondary school pupils admitted bullying others at least once a week, and 6.1 per cent were bullied at least once a week.
Far more are bystanders. A survey of 1500 pupils in primary and secondary schools by Dr Janis Carroll-Lind in 2002 found that 86 per cent had witnessed bullying in that school year.
The targets are usually people who are different in some way.
Victims in Youth 2007 said they were bullied because of their ethnicity (24 per cent), small size (13 per cent), religion (12 per cent), sexual orientation (7.5 per cent), or for unknown reasons (57 per cent).
