Wellmark Blue Cross and Blue Shield said today that it will seek a 9.35 percent premium increase for its under-65 individual policyholders. If approved by the Iowa Insurance Division, the rate increase would be effective April 1, 2012, for between 70,000 and 80,000 Iowa policyholders. The actual increase for policyholders will vary depending on age, plan design and other factors. Wellmark Chief Financial Officer David Brown said the company’s administrative costs of 12 cents per premium dollar is in the lowest quartile among U.S. health insurers.  The insurance division approved an 18 percent premium increase in May 2010 and an 8.5 percent increase — 2 percentage points less than requested by Wellmark —  in April. The requested increase does not apply to group plans or to Medicare plans, which are evaluated separately. A public hearing for the proposed rate increase will be from 11 a.m. to 12:30 p.m. Dec. 10 at the Urbandale Public Library, 3520 86th St. Comments may also be emailed to the Iowa Insurance Division consumer advocate at insurance@iid.iowa.gov.