The numbers, compiled by consultancy firm Gemba, were supplied to the Herald for a series of articles examining rugby's place in the national consciousness in 2017, which starts today.
They show our enthusiasm for sport across several measures - participation, passion, consumption and attendance - were falling between 2011 to 2015, though they have received a boost recently, possibly off the back of successful and popular rugby and cricket World Cup campaigns.
Sport NZ CEO Peter Miskimmin said the trends were in line with what the national funding agency was seeing.
"Traditional team competition sports is a really challenging space for us," Miskimmin said, citing figures that showed club membership was down 11 per cent since 1998.
Martin Snedden, who played a leading role in delivering a successful Rugby World Cup to New Zealand in 2011 believes the onus is on sports administrators to meet the changing needs of their constituents, even if it means blurring the lines between sport and entertainment.
Snedden said Auckland represents the biggest "challenge and opportunity" for the traditional team sports, with close to a quarter of its estimated 2.4 million citizens expected to identify as Asian by 2038.
"Where the growth of the Asian population represents a big opportunity for cricket - 43 per cent of adult cricketers in the Auckland area are of Indian ethnicity - for rugby it represents a huge challenge," Snedden said.
New Zealand Rugby is exploring new ways to engage with the Asian community, as have other sporting bodies.
Jenny Lim works with Harbour Sport as a capability manager and says while sport has "a bit of catching up to do" to engage with what is in itself a hugely diverse community, they are moving in the right direction.
"Surveys indicate that Asians participate less, especially in certain contexts like schools and clubs, but there is a desire to participate more.
"With more traditional 'New Zealand' sports, it could be a matter of improving access to information. How do we break down some of these barriers and let them know the values we can add to their lives?
"Everyone loves the All Blacks, it's a big part of New Zealand culture, so there is a desire to engage more."
Former Blues and Maori All Black halfback David Gibson said his sport needed to re-engage at community level.
"There is a definite disengagement there," he said. "I coach my son's team. Five years ago we had 13 age-group sides, this year we have three. I don't think rugby is less important, but its engagement and relevance at the community level is a challenge.
"I'm a big believer that rugby needs to change and adapt to meet the needs of its people."
Miskimmin said sport, including rugby, had for too long been locked into outmoded forms of supply that had failed to adapt to the demands of its customers, but said New Zealand Rugby bosses deserved credit for being proactive, encouraging diversity and sharing their intellectual property with other sports.
"Rugby has been such an important part of our social fabric and our national psyche that any change to [society] that effects it is going to be of great interest and concern," Miskimmin said.
The Book of Rugby series focuses on those challenges faced by rugby to retain its primacy in New Zealand. It looks at the explosion in importance of 1st XV rugby, and how that has brought both the positive and negative aspects of professionalism through the school gates.
It looks at how the product has changed, the safety issues enveloping the sport and how rugby may evolve as a multimedia spectacle to fit the demands of its consumers.
"Rugby is still the most consumed sport in New Zealand," Snedden said. "We want to read about rugby, we want to hear about rugby. That's the truth of it."
Authors note: The original version of this story stated that only about 8 per cent of adult New Zealanders considered themselves passionate about sport. This was a misinterpretation of the data. That figure was the average amount of New Zealanders passionate about the individual sports recorded in the survey.
