Go to the web site of the Federal Reserve Bank of St. Louis (FRED) (fred.stlouisfed.org) and find the most recent value and the value from the same month one year earlier for Excess Reserves of Depository Institutions (EXCSRESNS).

a. Using these data, calculate the percentage change in excess reserve balances between the two periods.
b. Based on your answer to part (a), briefly explain whether, holding all other factors that affect the money supply constant, the money supply should have increased, decreased, or remained the same during this period.