The Woodland Hills insurance company 21st Century Insurance reported that its net income for the third quarter increased 35 percent. The company credited the increase during the quarter ended Sept. 30 to higher income from premiums outside California. Net income totaled $28.4 million $0.33 per diluted share compared to $21.1 million $0.25 per share a year ago. The company in October announced that it was expanding into the New Jersey insurance market.