Complex sentence: At the 2001 New Zealand census, its population (including nearby wholly rural areas) was 831: 429 males and 402 females, a 23.1% increase in population since the previous census in 1996.
Split into simpler sentences: At the 2001 New Zealand census, its population (including nearby wholly rural areas) was 831: 429 males and 402 females. This was a 23.1% increase in population since the previous census in 1996.