The CarInsurance Premium Index (CPI) data listed on our site list the data that we have available at this time for the individual states monthly average premium amount for the previous 12 months. You can find it on each state page or on the bottom of the Premium Index page.
There is some state data on our site as far back as 2007 for the annual figures. You can access this information on the Historical Car Insurance Average Premiums pagefor state average rates compared to national average auto insurance rates.
We currently limit the monthly data per state to the previous 12 months, but offer the annual figures for the previous 3 years. We are not aware of where else you may obtain information the monthly averages for auto insurance rates. You may try the insurance regulators for the states you are interested in obtaining this information for to see if they have any other statistical information.