What is the longest - running number one single in New Zealand since Smashproof 's song " Brother " .
It is the longest - running number one single in New Zealand since Smashproof 's hit single " Brother " in 2009 , selling over 45,000 copies there , whereas in Australia , it is the longest - running number - one single since " I Wish I Was a Punk Rocker ( With Flowers in My Hair ) " by Sandi Thom in 2006 and the best - selling single of 2011 .