In Wairarapa, it widened by 3.5 per cent.
The Wairarapa figures were for Masterton, Carterton and South Wairarapa districts combined.
Wairarapa College principal Mike Schwass said there was a gap between the educational achievement levels of boys and girls at the school, but the size of that gap hadn't changed greatly over the past few years.
The school was working on closing that gap, for example by teaching novels that would appeal to boys.
"A lot of consideration and thought goes into deciding which books they do decide to go with."
Mr Schwass said the school was always looking at improving the academic performance of all students.
Ministry of Education associate deputy secretary, student achievement Lesley Hoskin said nationally boys were slowly closing the gap on girls in terms of NCEA achievement.
"Girls are still performing strongly, but boys are making good gains.
"We're aware that many schools have done a lot of work around supporting their boys to engage, aspire and work harder to achieve more."
She said the ministry's programmes aimed at lifting literacy did not discriminate on gender.