National robbery and theft rates have dropped sharply since 2001, the NSW Bureau of Crime Statistics and Research says.

In most regions the offences peaked about 2001, then declined through to last year, according to data based on reports to police.

The national robbery rate dropped 49.1% from 2001 to 2009, led by a 58.9% decline in NSW and a 39.8% fall in Victoria. The NT and ACT were the only areas to post increases.

National burglary rates fell 57.3% from 2001 to 2009 and motor vehicle theft dropped 62.2%, the bureau says.

Data collection changes make it difficult to compare statistics before and after 2009, but the report says it appears the trend continued in most cases.

Bureau director Don Weatherburn says the declines could reflect reduced heroin use, higher average weekly earnings and tougher law and order policies. “Changes in vehicle and household security and changes in police tactics may also have played a role.”

The bureau notes the statistics lack detail and concedes crime data does not give a complete picture, because a significant percentage of thefts and robberies are not reported.

NRMA Insurance says the crime rate is one of many issues considered when calculating premiums.

“While the frequency of thefts and robberies has decreased, other costs have increased over the past few years, including cost of replacement of items [and] repair costs,” a spokesman told insuranceNEWS.com.au.

Motor vehicle thefts increased 6% last year compared with 2011, according to Australian Bureau of Statistics figures released in June.