CHANGE IN RATES OF CRIME OVER TIME

INTRODUCTION

This section provides an analysis of changes in crime victimisation rates over the period 2008–09 to 2015–16 for selected personal and household crime types in Australia and in each state and territory.

Personal crimes include:

• Physical assault
• Face-to-face threatened assault
• Non face-to-face threatened assault
• Robbery (national level only)
• Sexual assault (national level only)

Household crimes include:

• Break-in
• Attempted break-in
• Motor vehicle theft
• Theft from a motor vehicle
• Malicious property damage
• Other theft

Year on year comparisons of crime victimisation rates alone often show little, if any, change and this type of comparison does not reveal patterns unfolding over a longer time period. To provide an overview of the general pattern in victimisation rates over time, functions were fitted to the data. Fitted functions give a better indication of changes over a longer time period.

The fitted functions in this analysis do not take into account the survey error associated with sample estimates, so other criteria were used in deciding when it was appropriate to apply this technique (see Technical Note for details).

Where functions were fitted, the analysis found declining victimisation rates for some crime types between 2008–09 and 2015–16 (as illustrated by the downward slope over time). In some cases, the fitted function appeared to increase for the most recent time periods, however, this apparent change was not statistically significant. Where there was no fitted function, any apparent patterns in victimisation rates over time should be interpreted with caution.

To assist in making comparisons, data series that did not meet the inclusion criteria for fitted function analysis have also been included in the line graphs, provided that the estimates were not subject to high survey error (see Technical Note).