InsWeb reported yesterday that the state of Michigan has seen a 5.4% increase in its median six-month auto insurance rate, over the last six months, making the average premium $688.

Also reported were some Michigan rate trends based on demographic groups, for example:

• Michigan women pay a median auto insurance rate that is at least 3% lower than the rate paid by men.
• Mature drivers in Michigan (those aged 50-59) pay less than half the median auto insurance rate charged to those drivers aged 19 and under.

According to the “affordability factor”, Michigan is the 24th most affordable state in which to insure a vehicle. Specifically, this means that a household in Michigan which earns the median state $44,727 a year, and pays the median rate of $688 (for six months) for auto insurance, is spending about 3.1% of it’s gross income for auto insurance.

Medians aside, Michigan is the most affordable state in the country, with an “affordability factor” of 2%, while Louisiana is the most expensive, with a factor of 7.1%.