Just over half of our current prisoners are Maori at 50.7 per cent, with Europeans next at 33.1 per cent, Pacific peoples at 11.7 per cent, Asians at 2.8 per cent and unknown making up the remaining 0.8 per cent.
About 80 per cent of prisoners are housed in minimum to low-medium security facilities, with the remaining 20 per cent held in high to maximum security prisons.
While penal reform groups want our incarceration rate brought down, conservative politicians and victims' advocates battle for tougher sentences and even hard labour for prisoners.
Policies like Act's three strikes legislation mean criminals now face longer jail terms - in some cases with no chance of parole.
But Conservative Party leader Colin Craig wants harsher penalties, saying criminals would be made to do "hard work" if his party is elected.
Corrections Minister Anne Tolley has set a target to reduce reoffending by 25 per cent by 2017 - one she says Corrections is already halfway to achieving.
More in-prison support programmes are being offered to more prisoners, such as a 1500 per cent increase in places on drug and alcohol treatment programmes for prisoners since 2008, she says.
That, together with education and mental health programmes gives offenders "the opportunity to turn their lives" and avoid returning to crime.
Mrs Tolley says the rate of offenders returning to prison within a year of release has dropped by 4 per cent since June 2011, and 3 per cent in the past year alone. But despite the gains, a new prison is being built.
Behind the figures
According to Corrections, in the year ended June 2014 more than 3700 prisoners had access to treatment for their addictions.
This figure is due to rise to 4700 this year, up from just 234 in 2007-08.
A further 2981 prisoners started literacy and numeracy programmes in the 2012-13 year, a significant increase on the 1162 in 2007-08.
The number of prisoners gaining qualifications increased by 830 per cent, up from 197 in 2008-09 to 1833 in 2012-13.
The total number of qualifications gained by inmates in 2012-13 was 3160 - giving them a better shot at building a productive life after their release.
Auckland University senior lecturer in criminology Dr Alice Mills says while increased access to support programmes is positive, courses are limited to certain types of offenders.
"Largely you have to be in prison for a certain length of time. They're often limited for women.
"You're only getting to a certain [part] of the prison population."
Short-term prisoners who are often "in and out" also need the programmes, she says.
The "Out of Gate" prisoner rehabilitation programme brought in last year, which targets the 6000 inmates released every year who serve two years or less, could help reach short-term prisoners, but the full impact has not yet been realised.
She is also concerned at how the Government measures the drop in reoffending rates within a prisoner's first year of release.
Reoffenders who commit a crime in their first year out of prison often take more than a year to pass through the court system, be found guilty, and receive a another custodial sentence.
Unless they are processed more quickly they might not be counted in the Government's reoffending figures, she warns.
Corrections says those figures refer to prisoners who have been imprisoned within one year of being released.
Mrs Tolley says Corrections is already halfway to achieving its target of a 25 per cent reduction in reoffending by 2017.
New prison
Dr Mills says it's problematic to compare our imprisonment rate to countries with lower rates - such as Scandinavian nations - because many have a fundamentally different approach to crime and punishment.
A country with a more closely-aligned system is the United Kingdom, with an imprisonment rate of 148 per 100,000 - not far behind New Zealand.
Penal reform groups want fewer people locked up and decry moves to build new prisons.
A new $300 million high-tech men's prison at Wiri, southwest of Auckland, is due to open next year.
The jail, which covers 17ha, is laid out according to the prisoner's journey.
Factors deciding where they are on the site include the seriousness of offending, length of sentence, level of risk and behaviour within the prison's walls.
The Howard League for Penal Reform has indicated support for the prison's rehabilitative model, but wants fewer prisons overall.
Dr Mills says the Government has been closing smaller, aging regional prisons such as those in New Plymouth and Mt Crawford in Wellington.
But although the older prisons were expensive to maintain, smaller regional prisons put inmates closer to community support networks and families.
"For people in Taranaki for example, it was keeping them much closer to their community and it was much easier to organise support for them on their release."
Determining what works
Penal reform group Rethinking Crime and Punishment founder Kim Workman says the system needs to embrace the rehabilitative model and move away from harsh sentences.
Locking people up for longer and treating them harshly will just make them less well adjusted on their eventual release, he warns, adding that most regular offenders stop committing crimes by about age 30.
"If you start putting people into prison for long periods you actually exceed that point and so they're sitting there costing us $94,000 a year and there's no benefit in it."
The United States - long considered the model for a country tough on crime - has started to move away from its traditional approach of locking up offenders and throwing away the key, Mr Workman says.
"They realised they can no longer afford it. In many states they're spending more money on prisons than they are on education."
As a result of a movement started by prominent US conservatives called 'Right on Crime', about 19 states have reduced prison numbers over the past two to three years, he says.
By reducing sentences, they found the people they released early committed fewer crimes on their release compared to those who stayed in prison longer.
He would like to see rehabilitation funding invested in community sentence programmes rather than putting more offenders behind bars.
But he admits judges are often put in a tough position.
"When someone is at the early stages of offending, and they want to do something rehabilitative - there's nothing in the community.
"So they tend to let them go until they get to a point where the judge says to himself, 'Well this guy's got a serious drug problem, the only place to fix that is in prison so I'll send him to prison'.
"We know that the climate in prison is not conducive to rehabilitation - the violence and negative environment.
"People aren't encouraged to take responsibility for their own behaviour."
Sensible Sentencing Trust spokesman Garth McVicar agrees more money should be invested into community sentence programmes.
By the time offenders get to prison they've racked up numerous offences,and it's harder to effectively treat someone with a drug or alcohol problem.
The rehabilitation would be easier if sentences were a firm and fixed length rather than allowing for a parole period, he says. Psychological services find it too difficult treating a prisoner on a nine-year sentence, for example, if they are paroled after three years.
However, Anne Tolley says her ministry is doing more than ever before to rehabilitate and reintegrate offenders.
"The vast majority of prisoners will be released back into communities.
"We don't want them creating more victims when they leave prison," she says.
"We need to do all we can to educate and train these people and treat their addictions and to give them the opportunity to turn their lives around so that they don't commit more crimes and end up back in prison."
APNZ