After sliding from a record $16.1 billion in 2004 to $6.9 billion in 2009 following enactment of SB 899, total California workers comp direct written premium has now increased 78% over the last 6 years, rising nearly 8% to a 10-year high of more than $12.3 billion last year according to NAIC data released by the Department of Insurance. CWCI examines the list of the top 20 insurer groups in the state in 2015 and how much their premium volume and market share changed from 2014.