Fewer than 16% of female victims in England and Wales report sex assault to police, according to new analysis that also reveals a third of all female victims were aged under 15.
While 5.7% of the population are aged 10 to 14 this age group accounted for 24.1% of police recorded sexual offences where the victim was female, the figures from the Office for National Statistics (ONS) reveal.
For the year ending March 2020, 773,000 adults aged 16 to 74 were victims of sexual assault, including attempts.
An estimated one in six of females aged 16 to 59 surveyed in the year to March 2020, who had been victims of sexual assault by rape or penetration since the age of 16, had reported it to the police, the ONS said.
This compares to an estimated 19% male victims reporting offences to police.
There were almost four times as many female victims at 618,000, compared to 155,000 men.
The victim was female in 84% of sexual offences recorded by the police, while 90% of victims of rape offences recorded by the police were female compared to 10% male, it added.
Data supplied by 24 police forces showed that females aged 10 to 24 years were “disproportionately” more likely to be victims of sexual offences recorded by the police.
A total of 162,936 sexual offences were recorded by police in England and Wales in the year ending March 2020, a drop of 0.7% compared to the previous year.
Helen Ross, from the ONS Centre for Crime and Justice, said: “Our latest findings from the crime survey showed a decrease in the prevalence of sexual assault in the year ending March 2020, though it should be noted that the current estimate is similar to levels seen over much of the last 15 years.
“The drop was driven by reductions in indecent exposure or unwanted sexual touching, however there was no change in the prevalence of rape or assault by penetration.
“In the same period the number of sexual offences recorded by the police has fallen slightly, after nearly tripling in recent years.
“The number of offences recorded by the police remains well below the number of victims estimated by the survey, with fewer than one in six victims of rape or assault by penetration reporting the crime to the police.”
The analysis, published on Thursday, is based on data on sexual offences from the Crime Survey for England and Wales and police recorded crime from the Home Office.
The ONS said that the prevalence of sexual assault experienced in the last year for adults aged 16 to 74 years at 1.8% was significantly lower compared with the year ending March 2019 at 2.4%.
But it said that it was too early to say whether the decrease in the latest year was the beginning of a downward trend or another fluctuation.
The ONS added: “Prior to this decrease, the number of sexual offences recorded by police had almost tripled in recent years.
“The increases in police recorded sexual offences seen in recent years largely reflected improvements made by the police in how they recorded these crimes and an increased willingness of victims to come forward and report.
“The latest decrease may reflect the diminishing impact of recording improvements.”