All members and policyholders of Medibank own the equity in the health insurance company, its own accounts clearly declare.Or so they did for several years to 1996. An historical survey of Medibank's annual financial statements by The New Daily over the last year throws a lot of doubt on the discretion of the Australian parliament to sell a business it cannot be certain the government owns.Only some people own Medibank - its policyholders. Their interests are referred to as "members' equity" in successive balance sheets presented in annual reports.This term principally features on the balance sheets of mutuals - credit unions, for instance.The sale of Medibank will thus be a more cumbersome process than proponents hope.