NEW YORK (Bloomberg) — US property casualty insurers used the lowest proportion of premiums for expenses and claims in two decades after losses plunged last quarter because of calmer weather.Insurers used 90.6 cents of every $1 in premiums collected to pay claims and expenses in the third quarter, the lowest ratio since Jersey City, New Jersey-based insurance data provider ISO began keeping records in 1986, the Property Casualty Insurers Association of America said in a statement today.

The industry took in $9.3 billion more in premiums than it paid out in claims and expenses during the last quarter, compared with a $15.2 billion loss during the same period a year ago, when Hurricanes Katrina and Rita battered the US Gulf Coast, according to the report. Insured catastrophe losses were $1.3 billion, compared with $48 billion a year earlier.

“Natural catastrophes still pose a huge threat to consumers and businesses along the Gulf and Atlantic coasts,” said economist Genio Staranczak of the Des Plaines, Illinois-based Property Casualty Insurers Association. “We view this development as an anomaly rather than a trend.”

Insurers such as American International Group Inc., the world’s largest insurer, and St. Paul Travelers Cos., the second- largest US commercial insurer, saw profit surge after neither of this season’s two major Atlantic hurricanes made landfall in the US.