According to data released by the Australian Bureau of Statistics on Wednesday, 89 per cent of the 183 sexual assault victims in the territory last year were women, a five-year low.

More than 40 per cent of sexual assault victims were aged 19 or younger while 59 per cent of assaults occurred in residential locations. Close to two in three victims knew the offender.

The ABS data is based on offences reported to police and a survey of households across the country.

The decline in sexual assault cases in the ACT was a contrast to the national increase of 3.3 per cent to 20,677 victims, although the sample size of the territory may have influenced the figures.

This was the third consecutive year the national number of sexual assault victims increased with the victimisation rate per 100,000 persons now at 88.

ACT Policing has previously urged caution when interpreting the ABS data given it is based on survey data and the relatively small size of the ACT.

"This report, taken within the context of reported crime statistics, provides some indication of which crime types may be under-reported to police," said a spokeswoman.

"Offences such as assault and sexual assault are traditionally under-reported to police, as for various reasons they can be complicated and difficult incidents for victims to talk about."

NSW Police Commissioner Andrew Scipione welcomed the crime statistics which revealed an 18 per cent decline in homicide, a 4.9 per cent drop in assault, and a 6.6 per cent reduction in vehicle theft.

"We have worked hard over the years in developing and improving on our victim care, and we actively encourage all sexual assault victims to report all incidents," he said.

The number of assault victims in the ACT dropped to 1705 with 26 per cent aged between 25 and 43.

Men accounted for 52 per cent of all assault victims with the offender known to nearly half of them.

Men were most likely to be assaulted in community locations while 59 per cent of female assault victims were reported being assaulted at a residential location.

The number of robbery victims in the territory remained stable at 162 with men accounting for three quarters of victims. Almost 50 per cent of robberies occurred on the street or at football matches while 23 per cent occurred at residential locations.

There was an 11 per cent increase in vehicle theft during 2014 with 752 cars stolen compared to 676 in 2013. Most vehicles were stolen in a community location while 34 per cent were stolen from homes in Canberra.

The ACT Policing spokeswoman previous stressed the survey was based on "respondent's perception of being the victim of a crime and may not necessarily correspond with the legal or police definitions used".