The cost of dog-bite claims for U.S. insurers climbed 16 percent last year on higher medical expenses and larger settlements to resolve court disputes.

The average claim increased to $37,214 in 2015 from $32,072 a year earlier, according to the Insurance Information Institute, an industry group. The average in Arizona was $56,654, the highest figure among the 10 states with the most claims. California has the second highest average cost per dog bite claim at $44,983 while New Yok, at $44,320, comes in third.

Health officials and companies such as State Farm Mutual Automobile Insurance Co. are seeking to limit the confrontations, which accounted for more than one-third of homeowners liability claims costs last year, the institute said. About 4.5 million Americans are bitten by dogs each year, and almost a fifth of those incidents require medical attention, according to the statement, which cited U.S. Centers for Disease Control and Prevention data.

“Most people don’t make a claim,” Kenneth M. Phillips, a Los Angeles attorney who represents victims of dog bites, said in an interview. “The reasons are pretty obvious: They might have been bitten by their own dog, or a family member’s or friend’s dog.”

The number of claims fell 7.2 percent last year to 15,352. Still, dog-related injuries cost the industry $571.3 million, up from $530.8 million. The average cost per claim nationally has risen 94 percent since 2003.

The increase in online shopping has added to risk for some mail carriers. While they can often put letters into a homeowner’s mailbox from the safety of their vehicle, a package delivery can require a trip to the front door.

Let Sleeping Dogs Lie

“The dogs are doing their job, they’re protecting their front porch,” U.S. Postal Service Safety Manager Linda DeCarlo said in a phone interview. “So it’s really important to us that we get the message to homeowners that if you’re expecting a package, put the dog in another room, close the door, help shut out these dog attacks.”

The institute also advises pet owners to be cautious about exposing pets to new situations and to discourage children from disturbing animals that are eating or sleeping. People should also avoid eye contact with dogs that appear threatening.

National Dog Bite Prevention Week runs from May 15 to May 21 this year.