Board of Governors of the Federal Reserve System (U.S.), 1935-. "Notes to Tables," in Board of Governors of the Federal Reserve System (U.S.), 1935-. "1990," Annual Statistical Digest (November 1991) : 170-183. https://fraser.stlouisfed.org/title/7/item/23496/toc/252151 , accessed on April 25, 2024.