Safe Driving

I got a new copy of my car insurance policy today, and it says "There are no male or unmarried female drivers under age 25 assigned to this car."

Ok, so I'm aware of the car insurance industry's unfair policy toward young men (despite being backed up by statistics, still unfair). But what's with this "unmarried" thing? Have I been being charged more all this time for not having a ring on my finger? And that would make me a safer driver how, exactly?