The South Korean pension system was created to provide benefits to persons reaching old age, families and persons stricken with death of their primary breadwinner, and for the purposes of stabilizing its nations welfare state. South Korea's pension system structure is primarily based on taxation and is income-related. In 2007 there was a total of 18,367,000 insured individuals with only around 511,000 persons excluded from mandatory contribution. The current pension system is divided into four categories distributing benefits to participants through national, military personnel, governmental, and private school teacher pension schemes. The national pension scheme is the primary welfare system providing allowances to the majority of persons. Eligibility for the national pension scheme is not dependent on income but on age and residence, where those between the ages of 18 to 59 are covered. Any one who is under the age of 18 are dependents of someone who is covered or under a special exclusion where they are allowed to alternative provisions. The national pension scheme is divided into four categories of insured persons – the workplace-based insured, the individually insured, the voluntarily insured, and the voluntarily and continuously insured.