Similarly, LSD (133) and cannabis seed (866) busts doubled last year and almost double the -heroin (18) was discovered than the year -before.
Methamphetamine interceptions rose from 114 in 2015 to 137.
The data shows meth interceptions have multiplied by over 11 times in five years. Busts in 2012 -totalled just 12.
Customs operations manager Lloyd Smith said the results were great news in the fight to uphold the integrity of New Zealand's border.
He said for smaller concealments, mail remained the method of choice for drug dealers, users and manufacturers.
"Mail is a really interesting place to look for drugs, partly because there's such a huge volume of mail. I had a manager who used to say 'the best place to hide a fish is in a shoal of fish'," Smith told the Herald on Sunday.
Smith said what the data didn't show was whether authorities were catching a higher percentage of concealments, or whether it -reflected an increase in attempts to ship narcotics into the country via post.
"To be honest, I don't really know. If you look at the rise in e-commerce over recent years, we've seen more and more people -becoming comfortable going on to the internet and ordering goods from overseas," he said.
"I think that's a real big part of it. Mail is the stream that most -internet shopping comes through and it's the same for what we call the dark net purchasing of narcotics.
"People are really, really comfortable with doing that sort of stuff."
Smith said new technology, -increased resources and closer ties with police had all helped -Customs' interception rates - which caught the eye of the UK Government.
Last month, Britain's Shadow Home Secretary, Yvette Cooper, said the UK could learn from New Zealand's strategy and multi--department approach.
"That is a compliment," Smith said.
"We don't really measure ourselves against other border jurisdictions, so to have that held up is really quite pleasing."
In total, Customs' preliminary data shows 3166 interceptions for all drug types at Auckland Airport's International Mail Centre in 2016 - 711 more than in 2015 and 1786 more than in 2012.
And Greg Newbold, Criminol-ogist and Professor at the University of Canterbury, said he didn't believe -the overall volume of drugs -inbound to New Zealand were -increasing significantly.
"My immediate reaction is that they're [Customs] becoming more efficient.
"Also, most of them would be lower--end interceptions. You get a few people sending a bit for somebody's birthday."
Smith agreed many mail busts were lower volumes. However, there had also been a number of massive breakthroughs recently.
A joint operation between -Customs and police landed a $14 million cocaine haul last year - the biggest ever seizure of the drug in this country.
Bricks of high-grade cocaine were hidden inside a diamante--encrusted statue of a horse's head.
Customs also landed its biggest--ever meth bust last year, when -officers rumbled an attempt to smuggle almost 200kg of meth - with an estimated street -value of $176m - into New Zealand -disguised as teabags.
Smith said meth was well-known to be New Zealand's "Class A drug of choice" and "at the moment we know we've got a massive meth-amphetamine issue"
