Nearly 172,000 people have signed up for health insurance via Colorado’s health care exchanges, a 9% increase compared to last year amid a tumultuous year for the health care industry.

The growth comes after the state opened an early enrollment period over the summer, which led to roughly 14,000 more people signing up. That itself was roughly a 9% boost. Leading up to the regularly scheduled enrollment period opening Nov. 1, health officials said they were expecting a “healthy” amount of enrollment on the exchanges. With a week still to go, that optimism has been realized.

“I’m thankful that so many people have found coverage through our Marketplace as the pandemic continues to devastate the health and wellbeing of our communities,” Kevin Patterson, the CEO of Connect for Health Colorado, said in a statement. “We’re here to help Coloradans secure financial help and choose a plan that gives them the care and peace of mind they deserve for this year.”

There are a handful of potential factors contributing to the growth, said Connect for Health spokeswoman Monica Caballeros, but more defined causes won’t be solidified until a follow-up report is completed over the next several weeks.

The pandemic is an obvious suspect. The earlier special enrollment period, launched a few months into the crisis, indicated a pressing need for insurance.

“From the perspective of how we think it’ll shape up, unfortunately, there are going to be more people shopping on the individual market simply because they lost employee-sponsored coverage,” Colorado’s insurance commissioner, Michael Conway, said in November. “If that turns out to be correct, we’re exceptionally happy that they have this option.”

Caballeros noted that 69% of those who enrolled via the exchange qualified for financial assistance, versus 74% last year. Enrollment is going up, while the share of people who need help paying for those health plans has gone down.

That itself may be caused by the state’s reinsurance program, which pays part of high health costs. Thanks to that program, prices on the exchanges were projected to be down by roughly 20% this year.

Although the Affordable Care Act, the sweeping federal health reform bill that created the exchanges, has been besieged by litigation, Colorado officials have said they weren’t too concerned about the Supreme Court potentially throwing out the law. That, too, appears to have paid off: At oral arguments before the court late last year, justices on both sides of the political aisle gave little indication that the law was in mortal peril.

Another cause of the growth, Caballeros said, is that there were more carriers this year, which would’ve allowed exchange customers to do more shopping around.

She said that overall, this enrollment period has been smooth, albeit with some technical difficulties initially.

Open enrollment remains open through Jan. 15. Coverage purchased via the exchanges will kick in on Feb. 1.