The average monthly cost for a 2015 mid-tier health insurance plan in the 35 states that are part of rose about 2 percent to $222 for a 27-year old, the U.S. government said on Thursday.

The figure represents the average premium for the second-lowest-cost silver plan, which is the benchmark plan used to set subsidy levels, the Department of Health and Human Services said.

The report from its Office of the Assistant Secretary for Planning and Evaluation covered the costs of plans sold on the website run by the federal government and created under the national healthcare reform law. The report did not include states that operate their own exchanges, such as California or New York.

Enrollment for individual coverage opened on Nov. 15 and closes Feb. 15. So far, more than 350,000 new customers have selected plans for 2015.

Last year, HHS also analyzed data for 48 states. It said that the average monthly cost, weighted for age distribution, was $328 for benchmark 2014 plans. It did not provide a comparable figure in the 2015 report.