National Assn. of Ins. Commissioners report that Calif. WC insurers posted a 7% return on net worth in 2008, but that was down from 12.1% in 2007 and less than half the return noted at the peak in 2006. The latest figures translate to a 10-year average after-tax gain of 3.5% for Calif. WC insurers, well below the nationwide average of 6.4 percent for WC insurers.