sentences:  Sunnynook South had a population of 5,538 at the 2018 New Zealand census, an increase of 417 people (8.1%) since the 2013 census, and an increase of 504 people (10.0%) since the 2006 census.There were 1,734 households.There were 2,769 males and 2,772 females, giving a sex ratio of 1.0 males per female, with 1,116 people (20.2%) aged under 15 years, 1,353 (24.4%) aged 15 to 29, 2,616 (47.2%) aged 30 to 64, and 450 (8.1%) aged 65 or older.