Most insurance companies use credit history to determine the likelihood that you will file a claim. According to The Zebra's "The State of Auto Insurance Report for 2016", drivers with poor credit scores (524 or less) have an average insurance premium of $2,411, while drivers with excellent credit scores (823 or higher) pay only $1,130 on average; a savings of 53%
Under the FACT Act amendments to the Fair Credit Reporting Act, you are entitled to one free annual credit report from each of the three major credit reporting companies in a 12-month period. You should know your credit score and be familiar with what has been reported regarding your credit. The Zebra notes that increasing your credit score by just one tier can save as much as 17%.
Here is a link for ordering a report from Transunion: