SACRAMENTO (AP) — Older Californians are continuing to enroll in the state's health exchange at a higher rate than younger residents, according to figures released Thursday.

Covered California, which operates the exchange, reported that more than 109,000 people signed up for a health plan through Nov. 30.

Nearly 60 percent were ages 45 to 64, although that age group makes up just a quarter of California's population. About 21 percent were 18 to 34, compared with their overall population of 25 percent.

Insurers say they need a higher percentage of those younger and typically healthier enrollees to make the policies financially viable.

The demographic numbers are naturally skewed toward the middle age brackets because many of those who qualify for the state health insurance program for the poor, Medi-Cal, are children and people over 65, and they are not included in the data. Kids under 18 are a quarter of the state's population.

Covered California officials have said they expected older people to sign up in greater numbers during the initial enrollment as people with pre-existing conditions or who had no previous insurance flocked to the website. People must sign up by Dec. 23 to get coverage starting in the new year.

The overall enrollment figure released Thursday is slightly higher than a preliminary federal figure released Wednesday, but still only about half the number projected before the exchange launched Oct. 1.