The H.15 historical data is available through the Data Download Program at:
http://www.federalreserve.gov/datadownload/Build.aspx?rel=H15

This series, H15/discontinued/H0.RIFSPPCM06_N.B, is available at:
http://www.federalreserve.gov/datadownload/Output.aspx?rel=H15&series=92f8996a5b038b8e1d5d587bb980fd3f&lastObs=&from=&to=&filetype=csv&label=include&layout=seriescolumn