If gas and milk price hikes seem steep, check out health insurance premiums. They have increased 10 times faster than incomes in recent years, a study shows.

Workers with job-based coverage for their families saw earnings rise 3 percent between 2001 and 2005, while their health insurance premium contribution increased 30 percent, according to the study by researchers at the State Health Access Data Assistance Center at the University of Minnesota.

The average cost of family coverage during the period increased by nearly $2,500 – that’s to $10,728, up from $8,281.

“Providing insurance coverage takes a bigger bite from the family budget every year,” said Risa Lavizzo-Mourey, chief executive of the Robert Wood Johnson Foundation, which helped finance the research.

Mohit Ghose, a spokesman for America’s Health Insurance Plans, the trade group representing the insurance companies, said the study shows the need for controls on the rising costs of drugs, devices and hospital care.

He also said it showed the need for regulators and lawmakers to give insurers the flexibility to offer plans with fewer mandated benefits. That would allow insurers to offer more affordable premiums to employers.

“The aim is keeping them in,” Ghose said. “The worst-case scenario would be that employers would drop coverage altogether.”

The study found that was already a big problem. Between 2001 and 2005, more than 30,000 of the 3.6 million private-sector employers offering health insurance as a benefit to workers dropped it.

As a result, the number of people in private-sector jobs that offered health insurance benefits declined by more than 4 million, and the number of people with private insurance declined by 2.4 million, or 6 percent, the study found.

The study is one of several examining problems with and the erosion of private health insurance. On Monday, another study warned that the worsening economy would put pressure on government health coverage programs.

Each percentage-point rise in the nation’s jobless rate could add 1.1 million people to the ranks of the uninsured, according to the study by the Urban Institute for the Kaiser Family Foundation.

That study also found that 7 percent of Americans said they or someone in their household decided to marry in the last year so they could obtain health care benefits via their spouse.

The University of Minnesota study found that the proportion of insurance premiums workers paid for job-based family coverage between 2001 and 2005 held steady at 24 percent with employers picking up the balance.