**Complaint Index -** A mathematical comparison of an insurance company's premium volume against its number of closed consumer complaints filed with the department during a given calendar year. Generally speaking, an index of 1.00 means the company's share of closed complaints is equal to its market share. For example, if a company has 25% of the market a complaint index of 1.00 means it also has about 25% of the closed consumer complaints. An index greater than 1.00 (for example, 1.50) means the company has more closed complaints than its share of the market; and an index less than 1.00 (for example, 0.75) means the company has fewer closed complaints than its share of the market.