Figures from the Home Office show there were 105,181 crimes reported to Devon and Cornwall Police in the year to September 2022 – 5,993 (5.7%) of which led to a charge or summons.
This was down from 7.7% in the year to September 2021.
Of the broader types of crime, possession of weapons offences had the highest prosecution rate in Devon and Cornwall, with 22.8% of crimes leading to a charge or summons.
Meanwhile sexual offences had the lowest, at just 2.2%.
Across England and Wales, sexual offences have been in the spotlight due to low prosecution rates and a surge in the number of offences recorded.
Rape has the lowest charge rate across all crimes, with just 1.6% of 70,633 offences recorded by police leading to prosecution across the two countries in the year to September 2022.
More than 40% of rape investigations were closed because the victim did not support further police action.
In Devon and Cornwall, the charge rate for all sexual offences has fallen from 4.1% in the year to September 2021.
Labour’s shadow home secretary, Yvette Cooper, said rape victims are being “systematically let down by this government, with action against rapists totally failing to keep up with record levels of reporting”.
She urged: “Victims of these hideous crimes need and deserve the best possible support.”
Diana Fawcett, chief executive of charity Victim Support, said: “This huge rise in recorded sexual offences comes as the percentage of cases seeing justice has plummeted to an abysmal new low.
“Charges for rape and sexual offences have been falling sharply for the past six years – the system is in crisis,” she added.
For all types of crime, the figures show just 5.5% of offences in England and Wales resulted in a charge or summons in the year to September 2022.
This was down from 6% a year before – although this excludes data from Greater Manchester Police because of problems the force had recording crime at that time.
The rate of prosecutions has generally declined over the years and is now less than half the percentage in the year to September 2015 (14%).
Minister for Policing, Crime and Fire Chris Philp pointed to reductions in a number of different types of crime, such as burglaries, serious violence and murder.
But he said "there is much more to do" to protect women and girls.
He added: “With huge efforts under way across the criminal justice system, we are now starting to see signs of improvement in the number of charges and prosecutions.”