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/H1.RIFLGFY10P_N.WF, is available at:
http://www.federalreserve.gov/datadownload/Output.aspx?rel=H15&series=6f51f2b2efd7e78fcc26efecb7875e1c&lastObs=&from=&to=&filetype=csv&label=include&layout=seriescolumn