The median six-month auto insurance rate in Washington has remained steady over the last six months, increasing less than 1 percent to $637 according to InsWeb, an online insurance comparison provider.

A Washington household that pays the six-month median rate of $637 and earns the Washington household median annual income of $45,909 pays about 2.8 percent of its gross income for car insurance.

According to InsWeb's car insurance affordability index, Washington is the 16th most affordable state in which to insure a vehicle. Currently, Massachusetts is the most affordable state with an affordability factor of 2 percent, while Louisiana is the most expensive with a factor of 7.3 percent.

Men in Washington pay a median auto insurance rate that is about 10 percent higher than the rate paid by women. The median six-month rate for men is $664 and $603 for women.

Drivers in Washington 19 years of age and younger pay a median auto insurance rate ($1,279) that is more than double the rates paid by every other age segment except those ages 20-24 ($902) and 25-29 ($697).