Frequencies for measurestartdatestr variable in hqi_national_comp dataset :

    Measure |
 Start Date |      Freq.     Percent        Cum.
------------+-----------------------------------
 04/01/2012 |          1        9.09        9.09
 07/01/2013 |         10       90.91      100.00
------------+-----------------------------------
      Total |         11      100.00

by Jean Roth , jroth@nber.org , 15 Nov 2016