Counting Crime: check out your neighbourhood at Herald Insights here.
Some of the most violent areas were Wellington City, including the hotbed from Willis St to Cambridge Terrace, which had 4312 cases.
Auckland Central had 3485, Hamilton City had 6063, and Counties-Manukau West had 5886, while the Canterbury Metro Area (Christchurch) had 10,417.
Acting Assistant Commissioner Sam Hoyle said the stats were not a surprise and there was a "strain" on police resources to help keep the peace.
"If you look at our biggest CBDs they all feature around those common assaults, which doesn't surprise me at all.
"Where we have those strong night-time economies where we have big groups of people all arriving in town at the same time, often having preloaded before they arrive, and then they all leave at about the same time we get people bumping into each other and that's where we get the assaults.
"At four o'clock on a Sunday morning there's not much around in terms of capable guardianship, there's some police officers, some security, taxi operators - there's not that much else out there in terms of capable guardians."
He said often assaults involved "predominately younger people [who were] heavily intoxicated".
He said police "resource-up" for every Thursday, Friday and Saturday night to help combat the carnage.
Large public events, such as a concerts, receive the same treatment.
"It does put a strain on, it's a busy period for police most weekends, it's a busy period for ambulance staff, it's a busy period of ED [emergency department] staff for all those same reasons."
Police statistics also show more than a third of all offences are committed by an offender who has been drinking.
On an average day in New Zealand some 52 people are taken home or detained in police custody due to their state of intoxication. And on average 340 offences occur where police see alcohol as a factor in the offending, including 100 drink-drive offences and 30 breaches of a liquor ban.
Statistics are sourced from the Police national data page and are for July 2014 to December 2016 with an outcome of investigation of 30 days.
Wellington CBD & Cathedral Square: The most dangerous places in the country?
Hoyle said Wellington's inner-city was a hotbed for violent offences on a Friday or Saturday night.
However, it was similar to any big CBD in the country, where a large number of people congregated after "pre-loading" on alcohol and attending night-time events.
He said the same could be said for Christchurch Metro, which was ranked top for the area in New Zealand for sexual assault cases from mid-2014 to the end of 2016.
Many of the same factors associated with assaults around the country were also found in aggravated sexual assaults incidents.
"Central Christchurch as we know is sort of reopening and reinvigorating and nightlife is coming back. It hasn't featured amongst the data much at all until the last year or two [due to the earthquake recovery]," Hoyle said.
"These types of sexual assaults [tend to result from] big groups of people dispersing from clubs and pubs in the early hours of the morning. Generally these sexual assaults are not committed by strangers.
"Stranger attacks are still incredibly rare in New Zealand, which is a great thing. Generally the parties are known to each other in one way or another and often there is a degree of intoxication."
Despite a high number of hotels and backpackers in downtown areas, Hoyle said there was no evidence to suggest that tourists were sexual assault targets.
Historically data, he said, suggests the vast majority of victims are locals making their way home through a more dangerous part of town.
Police have said one reason many sexual assaults are recorded in downtown Christchurch is because many crimes are reported at the central police station, due to police being unable to determine an exact the location.
Statistics are sourced from the Police national data page and are for July 2014 to December 2016 with an outcome of investigation of 30 days.
Read more stories from the series here:
• Counting Crime: 'His life has been erased'
• Counting Crime: Our country's violence fuelled by liquor
• Smash and grab victim: 'just don't leave stuff in your car'
• Car stolen by brazen thieves as couple slept 5m away
• An in-depth look at offending and victims in New Zealand
• Thefts from cars - when, why, how and who
• Retailers in harm's way
• Retail thefts cost country $1.2b
• Small business owner more vigilant
