Chiropractors now account for a greater share of total provider charges in Minnesota's no-fault insurance system than all other types of treating providers combined. According to a new study from the Insurance Research Council (IRC), 58 percent of all provider charges for treatment of no-fault insurance claimants in 2007 were from chiropractors. In a study conducted five years earlier, IRC found that 41 percent of all treatment charges were from chiropractors. The recently released study, Analysis of No-Fault Auto Insurance Claims in Minnesota, is based on a detailed review of more than 500 personal injury protection (PIP) insurance claims closed with payment in 2007. The claims were among the 42,038 claims examined in the IRC's countrywide report, Auto Injury Insurance Claims: Countrywide Patterns in Treatment, Cost, and Compensation. The growing cost of chiropractic treatment in Minnesota's auto insurance system is attributable primarily to rapid growth in average charges per visit to chiropractor offices. Between 2002 and 2007, average chiropractor charges in Minnesota increased 30 percent, from $122 to $158 per visit. In addition, the percentage of PIP claimants receiving chiropractor treatment increased approximately 5 percent. Minnesota had the third highest utilization rate for chiropractors (42 percent) among 17 states with no-fault insurance claims. Only Washington and Florida had higher chiropractor utilization rates in 2007.