[Kalium]

(Disclosure: I work for a car insurance company. I am not an actuary and have no special insights into how premiums are calculated.)

Gender famously matters too - a 18/M is (statistically) likely to be a worse driver than a 18/F. Rates reflect this. Having once been a 18/M, I have no trouble believing this.

That said, it's very difficult to compare across states. Car insurance is regulated at the state level, so inevitably different states (or territories, or DC, etc.) have made different choices over time. You can do a dollars-to-dollars comparison between any two states but there's a good chance the elements of the policies and liability rules aren't the same.

I suspect there's also some adjustment to premiums done for how much it costs to repair things where you live. Medical care, building repair, and car repair are all things that likely come up a lot on claims. If you're some place where these are twice national averages, you might have higher premiums than you would in a place where these cost half the national average. In addition to the chance of a loss varying by location.