Source: Board of Governors of the Federal Reserve System (US)
Release: H.15 Selected Interest Rates
Yields on actively traded non-inflation-indexed issues adjusted to constant maturities. The 30-year Treasury constant maturity series was discontinued on February 18, 2002, and reintroduced on February 9, 2006.
For further information regarding treasury constant maturity data, please refer to the H.15 Statistical Release notes and the Treasury Yield Curve Methodology.
Board of Governors of the Federal Reserve System (US), Market Yield on U.S. Treasury Securities at 30-Year Constant Maturity, Quoted on an Investment Basis [DGS30], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/DGS30, March 28, 2023.