The Federal Reserve Bank of St. Louis publishes a weekly index of financial stress (FRED code: STLFSI) that summarizes strains in financial markets, including liquidity problems. For the period beginning in 1994, plot this index and, as a second line, the difference between the Baa bond yield (FRED code: WBAA) and the 10-year U.S. Treasury bond yield (FRED code: WGS10YR). Does the index STLFSI provide an early warning of stress?