The percentages were the total number of tests passed as a percentage of total completed tests.
Allan Koller from Rotorua's Allan's Driving School said in his view professional tutoring was behind the growth.
"I'd like to say that's probably why the pass rate is increasing: because more kids are getting tuition from professionals rather than just their parents."
He said more students were booking a single lesson just before their test, or turning up after they'd already failed before their next test.
However, Mr Koller said he didn't think the full licence tests - for the permission they were granting - were as difficult as they should be.
"At no stage are you taken out on the open road, when you used to be ... I think it's a time factor thing. The full licence test now is only a 20 minute drive, so they can't afford to take you out of town in case they hit something untoward like road works, and they'd miss their next drive.
"It's a 20 minute drive. There's no parallel parks, no three point turns. It's just a drive around Glenholme and Fenton Park."
Roger Venn, Automobile Association general manager of driver training, agreed that pass rates had increased in part due to a growing use of professional instructors.
"The way we used to learn, with parents, grandparents, siblings - there's a general realisation that we don't have the skill sets to get our young drivers not only just through the test but to [learn to] drive safely."
He said in parts of Europe and the US, drivers had to have a certain number of hours with a professional instructor to get their licence.
He also said pass rates were comparatively low in New Zealand compared to other OECD countries, and therefore increases weren't unexpected.
However, just because a driver had their licence didn't mean they should stop educating themselves, he said.
"I would encourage all young drivers, and their parents, to concentrate on maybe taking some additional training, and the defensive driving course is a great course for that.
"People need to take a responsibility for their actions. It's the most dangerous thing you're going to do every day pretty much, and people are so blasé [about it]."
NZTA's road safety director, Harry Wilson, said it was difficult to draw any conclusions comparing different regions' pass rates.
"The best determinant of whether an applicant will pass or fail is their preparation. The drive.govt.nz website is a key tool to help people get ready for their driving test."