Frequencies for first 10,000 rows of dlmp_yy variable in natl2008 dataset :

Last Normal |
   Menses - |
   Year U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
       2007 |      9,788       97.88       97.88
       2008 |          1        0.01       97.89
       9999 |        211        2.11      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 May 2016