From the HealthIT.gov website:
"All referenced national level measures are provided for the most recent period of data in the 'all U.S.' report. All referenced state level measures are provided for the most recent period of data, in addition to at most two years of preceding trend data. State level measures are visualized side-by-side with national level measures for state-specific reports. All of the data is fully accessible, with full data documentation, through the Dashboard."