California's largest health insurers are raising average rates by about 8% to 14% for hundreds of thousands of consumers with individual coverage, outpacing the costs of overall medical care. The cost of goods and services associated with medical care grew just 3.6% over the last 12 months nationally, government figures show. But insurance premiums have kept climbing at a faster pace in California. Insurers defended their rate hikes, saying they are based on their claims experience with the customers they insure and not just the broader rate of medical inflation.