Frequencies for msr_strt_dt variable in vwmeasure_dates dataset :

msr_strt_dt |      Freq.     Percent        Cum.
------------+-----------------------------------
  01oct0200 |         18       25.71       25.71
  01oct0201 |          3        4.29       30.00
  01jul2007 |          6        8.57       38.57
  01jan2009 |          4        5.71       44.29
  01apr2010 |         37       52.86       97.14
  01jan2011 |          2        2.86      100.00
------------+-----------------------------------
      Total |         70      100.00

by Jean Roth , jroth@nber.org , 16 Nov 2016