The Office of the Prime Minister’s Chief Science Adviser website is a great resource for facts about the upcoming New Zealand Cannabis Legislation and Control referendum. 

The Office have found that 80% of New Zealander’s have tried cannabis at some point in their lives.  They conclude

It is very common to have tried cannabis and common to occasionally use cannabis even though it is illegal

With this in mind we can safely conclude that 80% of the people in Wellington have indeed tried cannabis.   Given cannabis use is widespread, why continue with legislation?  The illegality of the plant seems to have no impact on its use, so there is little point in maintaining the expense of fighting drug use with out dated laws.