People sign up for health insurance information at a Covered California event which marks the opening of the state's Affordable Healthcare Act, commonly known as Obamacare, health insurance marketplace in Los Angeles, California, October 1, 2013. REUTERS/Lucy Nicholson

(Reuters) - Nearly 80,000 Californians have enrolled in private health insurance plans through the state’s exchange marketplace created under President Barack Obama’s healthcare law, the Covered California exchange said on Thursday.

The latest data, which charts enrollment from the October 1 start through November 19, means that about 20,000 more people signed up for plans since the exchange’s initial update on its enrollment released November 13.

California, which is the most populous U.S. state and embraced the Affordable Care Act early on, is considered a crucial region for the administration’s enrollment effort. The state is one of 14 operating their own exchanges, as opposed to relying on the federal government.

Last week, the U.S. government released initial data showing that 106,000 people had enrolled in new exchanges nationwide from October 1 through November 2. California’s enrollment amounted to about one-third of all sign-ups during that period and outnumbered the combined tallies of all 36 states that use the faulty HealthCare.gov website operated by the federal government.

Covered California also released data on Thursday showing that nearly 23 percent of the sign-ups during the first month of enrollment were 18 to 34 years old, while 34 percent were 55 to 64 years old.

Those age breakdowns are in line with other early data released by four other state exchanges, showing that more older adults have signed up for the new plans than younger Americans so far.

The age balance is being closely watched to determine the financial stability of the insurance market created by the Affordable Care Act, as the participation of younger people is needed to offset costs for sicker beneficiaries. Health policy experts and actuaries told Reuters it was premature to draw any conclusions about the early demographic data.

The rate of enrollees in the younger age group is similar to the overall California population, Peter Lee, executive director of Covered California, told the exchange’s board of directors in a presentation on Thursday.

An estimated 7 million Americans are expected to sign up for plans through the new exchanges for coverage next year, while California’s exchange has said it is aiming to sign up 1 million to 1.4 million people in 2014.