Australia has one of the highest rates of reported sexual assault in the world, at almost 92 people per 100,000 of the population, according to the United Nations. Another survey has quoted the Australian rate at more than double the global average.

According to the UN, Australia ranks below on South Africa in rates of reported rapes.

Countries such as Swaziland, Canada, Jamaica and Sweden follow with rates of reported rape per 100,000 of the population coming in at 76.1, 68.2, 50.8 and 40.6 respectively.

Neighbouring New Zealand reported a rate of 32.2 per 100,000 of the population, ahead of England and Wales at 25.6.

Related reading Calls for changes to the legal system for sexual assault cases

But making global comparisons is difficult, with survey results varying greatly. Comparisions are also particularly difficult with many developing countries and those suffering from war, as police records often don’t exist and reporting assault to authorities might not be an option.

In Australia rape and sexual assault statistics are collected by state.

In NSW there were 3,951 separate sexual offence incidents reported to police in 2013. In that year 715 people were charged and 374 were found guilty, a conviction rate of 52 per cent for the state.

Of those 374 found guilty, a total of 168 people received a full time prison sentence, representing approximately four per cent of the incidents originally reported to police.

The figures show the likelihood of a sexual assault offender serving a prison sentence is pretty low, especially because it's believed that most sexual assault incidents are not reported to police.

It should be noted that in a 2010 review into the handling of rape complaints in the UK, Vivien Stern warned that the focus on the conviction rate could have a negative effect because it may deter victims from reporting incidents.

Baroness Stern said rates could be “misleading and deeply unhelpful”, particularly in regards to encouraging women to report offences and work with authorities. She said the treatment and recognition of victims by authorities could be viewed as on par with a conviction.

But in Australia there are calls for changes to the court system to address the disparity between the numbers of alleged offences and convictions.

Rape support workers say many victims are put off pursuing charges because of lengthy court processes and difficulties with meeting the extensive requirements for proof.

Related reading A rape victim's story: Six months of assaults, five years in court

The traumatic experience of the court system has also been blamed for the high rate of underreporting, with one Canberra support worker describing rape as “the most underreported crime in our community”.

According to figures issued by the Australian Institute of Criminology, an estimated 70 per cent of sexual assaults incidents are not reported to police.

Associate Professor Heath said international figures were just as bad, suggesting that only about 15 to 25 per cent of sexual offences were reported.

She said even when reported, only a fraction of those that get to court result in conviction.

“The best national data suggests we have a reporting rate of 15 per cent of all sexual assaults victims say took place, while only 11 per cent of those reports to police result in convictions,” she said.

“Eleven per cent of 15 per cent means the actual conviction rate relative to the number of offences committed is minuscule.”

Around Australia

Figures from Victoria Police show a 51 per cent increase in reported rapes over a 10-year period between 2004 and 2013-14, which recorded a total of 2,095 offences across the state’s four types of rape (including common law).

Increases in reported rape could be due to a variety of reasons, according to the Australian Institute of Criminology, including a greater awareness about what sexual assault is.

Rates in other states have remained relatively steady, with NSW annual reporting figures ranging between 3,951 and 4,255 in the eight year period to 2013.

South Australia was similarly steady, with reported cases ranging from 697 in 1994 to 691 in 2007.

How we compare: Rate of reported rapes per 100,000 of the population

Women who are experiencing sexual or physical violence are encouraged to ring 1800-RESPECT, a national telephone support line.