With only one upheld complaint, Amica Mutual Insurance Co. of Rhode Island, a perennial top 10 finisher, ranked the best among 49 auto insurers or groups ranked by the New York State Insurance Department in its most recent complaint report. Joining Amica at the top of the rankings for fewest upheld complaints were USAA, Erie, Preferred Mutual, Credit Suisse, Atlantic, American Modern, Electric, Royal & SunAlliance, Harleysville, Response, Central Services, Eveready, National Grange, State Farm, Chubb, Unitrin, Merchants Mutual, Progressive, Liberty Mutual, Utica National, Amex, CNA and Allmerica. Many of the best performers had relatively small market share in the state. Of the largest auto insurers in the state, both Allstate (the state’s largest insurer with 16.6 percent of the market) and State Farm showed significant improvement, according to the department. Both registered complaint rankings better than the overall average, while the ratio of the second largest insurer, GEICO, was below the average for all insurers. The rankings for the 10 largest auto insurers in the state showed Allstate (ranked at 32), GEICO (38), State Farm (15), Progressive (19), Travelers (27), Liberty Mutual (20), AIG (40), White Mountains (36), New York Central Mutual (12), and Nationwide (26). The worst performers in positions 40 through 49 were AIG, Lumbermens, Mercury Casualty, Fairfax Financial, Safeco, Great American, Clarendon, Infinity, Interboro and Leucadia.