"It has been estimated that a very low proportion of the Australian general population aged 14 years and over have ever injected or recently injected drugs. In 2010, 1.8% of the population had injected a drug in their lifetime, with 0.4% having injected a drug in the past year. More than one-quarter (27.1%) of recent users injected daily and the majority obtained their needles and syringes from a chemist (64.5%). Males were more likely to have recently injected drugs in the past year than females (0.6% versus 0.3%). Those in the 20-29 and 30-39 year age groups had a higher proportion of past-year injecting drug use (0.9% for each) than those in other age groups (Australian Institute of Health and Welfare, 2011).
"Another recent prevalence estimate of injecting in Australia in 15-64 year olds is 1.09% (range = 0.65%-1.50%) which equates to approximately 149,591 persons (range = 89,253-204,564) (Mathers, Degenhardt, Phillips et al., 2008)."

Source

Stafford, J. and Burns, L. (2013). Australian Drug Trends 2012. Findings from the Illicit Drug Reporting System (IDRS). Australian Drug Trend Series No. 91. Sydney, National Drug and Alcohol Research Centre, University of New South Wales. p. 104.
http://www.ndarc.med.unsw.edu.au...