More than 4000 emergency calls to police were abandoned in 2011.
Figures released under the Official Information Act show 4149 national emergency calls to police were abandoned in 2011, down from 5716 in 2010 and 7063 in 2009.
Abandoned calls were at their lowest – 3406 – in 2008.
Calls are considered abandoned when they are not answered after two minutes and are re-entered into the queue, when the event is escalated before police take over the call from Telecom, or when the call was put through to the wrong emergency service.
Superintendent Dave Trappitt, acting national manager communication centres, said it was wrong to suggest all the calls went unanswered.
"We either answer every call or if the person hangs up or is disconnected, we make every effort to contact them back to make sure they're OK," he said
Trappitt said provisional figures for 2012 showed 1356 calls were abandoned.
The percentage of calls involved was very low, he said.
In 2011, 727,124 calls were extended to police by Telecom operators. That did not include calls put through to other emergency services.
Trappitt said the goal was to answer 90 per cent of emergency calls within 10 seconds, and in the 2011/12 financial year police achieved 92 per cent.
"The other side of the equation is caller behaviour, which also drives abandonment," he said.
"Even under emergency circumstances some callers will hang up, or their situation has changed and they no longer need police."
Green MP David Clendon said while there had been an improvement, abandon rates were still too high.
"People rely heavily on 111," he said.
In a perfect world all calls to 111 would be answered quickly.
Clendon said he accepted there would always be some malicious or prank calls but the rate could be better.
"They are emergency calls after all. People don't dial 111 lightly," he said.
Clendon said improvements needed to be made urgently.