This figure shows notified cases of IPD in Australia for the fourth quarter of 2013, by 5 year age groups. The figure demonstrates notified cases were highest in the under 5 year olds, followed by the 60 to 64 years old age group and the 65 to 69 years age group. While this distribution was evident in non-Indigenous Australian cases, in Indigenous cases IPD was most prevalent in cases aged under 5 years and those aged 25 to 29 and 45 to 49 years.