At this point, you've probably heard that health insurance premiums under Obamacare are set to rise an average of 25 percent next year. But beyond the headlines and partisan spins, one detail that seems to have been overlooked is that those increases will vary dramatically from state to state.

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For example, as reported by Business Insider, consumers in Arizona will see their premiums rise by 116 percent, while consumers in Indiana can actually expect to pay three percent less for their premiums. One of the main reasons for the difference has to do with the demographic breakdown of enrollees in each state; states with older populations more prone to illness are costlier for insurers, causing premium spikes. 

That's not to downplay the issue, of course. Even a modest premium hike will have a financial impact for individuals who don't qualify for federal subsidies. And, as the Obama administration emphasized, these subsidies will also increase in order to offset rising costs. But this map offers some perspective on the true nature of the health insurance changes that may have been amplified by the media.

Rates will also vary based on the number of insurers in each state.

Another factor behind the state-by-state premium differences is that insurers are increasingly pulling out of state exchanges, leaving consumers with fewer options. In Arizona, which will experience the highest spike in premium costs, the number of insurers operating in the state will drop from 11 in 2015 to only two in 2017.

"Most economic research shows that concentrated insurance markets tend to have higher insurance premiums — and the areas of the country with the steepest Obamacare rate hikes next year tend to be the places with just one insurer," Vox reported.