As social security is the largest government program in the world, there are many social security numbers associated with the program. Perhaps the most important of these numbers is 40%- which is the number of elderly over age 65 that are kept out of poverty by social security. Another key number is #1- as in social security is the #1 government program in both the US and the world, based on size and money spent. In 2004 alone, 20.8% of the federal government budget was spent on social security, compared to 20.5% for defense spending. This constitutes 37% of government spending and 7% of the gross domestic product. Social security was passed into law in 1935 multiple times every decade of its existence. Social security is funded by dedicated payroll taxes, which are split 50/50 between employers and employees and paid for entirely by the self-employed, to the tune of 15.3% of and employee's gross wage amount, up to but not exceeding the Social Security Wage base of $106,800 for 2009. This amount is adjusted annually for inflation.