The number of rapes recorded by the police in England and Wales has risen by 31% in the past year to 24,043 – the highest level for at least 10 years, according to the Office for National Statistics.

The official statisticians ONS say the increase in rapes and a 22% rise in all sexual offences reflects a greater willingness among victims to come forward to report attacks as well as better recording by the police.

The rise in reported rape is revealed in the authoritative quarterly crime survey of England and Wales published on Thursday, which shows an 11% fall in overall crime levels in the 12 months to September 2014 compared with the previous year. The separate measure of police recorded crime shows no change in the 12 months to September 2014.

The 11% fall, based on people’s experience of crime, confirms a continuing downward trend in overall crime levels, now at their lowest since 1981. Particularly strong falls were seen in car crime and criminal damage, both of which fell by 15% according to the official crime survey.

ONS statisticians said the renewed focus on improving the quality of police compliance with national standards for the crime figures led to more crimes being recorded than previously. They point to findings in the crime survey, which interviews 40,000 people, that there has been no significant long-term change in the rate of sexual offending as evidence that the increase in rape figures reflects better reporting and recording than a real rise in attacks.

The figures also show a 5% increase in the volume of fraud, including online fraud, to 212,699 incidents reported to the police in the past 12 months. ONS statisticians say online fraud is now more prevalent than the “traditional” crimes of robbery and theft from the person, though the figures are beginning to plateau.

The latest crime survey of England and Wales shows that there were an estimated 7m crime incidents against households and adults in the 12 months to September. This is more than 60% below the 19m crimes estimated when crime peaked in 1995, since when it has been falling every year for the past 19 years.

The police-recorded crime figures, which have lost their national statistics status because of recording issues in January last year, show 3.7m offences recorded by the police. They include 507 murders in the 12 months to September – 8% fewer than the previous year.

Home Office minister Lynne Featherstone said crime had fallen by 20% since the last election and by 63% since its peak in 1995: “This is good news for a safer England and Wales,” she said.

“In 2013, the home secretary commissioned Her Majesty’s Inspectorate of Constabulary (HMIC) to carry out an inspection of police crime recording in all forces, and expects chief constables and police and crime commissioners to act on its recommendations. We are already seeing the benefits of HMIC’s scrutiny in more accurate crime recording. In addition, more victims of sexual offences and violent offences are coming forward – this is something we welcome.”