As of September 30, 2000 and 1999, federal debt managed by the bureau
totaled about $5,659 billion and $5,641 billion, respectively, for moneys
borrowed to fund the government’s operations. These balances consisted
of approximately (1) $3,439 billion as of September 30, 2000, and $3,668
billion as of September 30, 1999, of debt held by the public and about
(2) $2,220 billion as of September 30, 2000, and $1,973 billion as of
September 30, 1999, of intragovernmental holdings.
http://www.treasurydirect.gov/govt/reports/pd/feddebt/feddebt_ann2000.pdf
As of September 30, 2008 and 2007, federal debt managed by the bureau totaled about $10,011 billion and $8,993 billion, respectively, primarily for moneys borrowed to fund the federal government’s operations. As shown on the Schedules of Federal Debt, these balances consisted of approximately (1) $5,809 billion as of September 30, 2008, and $5,049 billion as of September 30, 2007, of debt held by the public and about
(2) $4,202 billion as of September 30, 2008, and $3,944 billion as of September 30, 2007, of intragovernmental debt holdings.
http://www.treasurydirect.gov/govt/reports/pd/feddebt/feddebt_ann2008.pdf