Frequencies for first 10,000 rows of dlmp_yy variable in natl2014 dataset :

Last Normal |
Menses Year |
  nnnn Year |
    of last |
     normal |
     menses |      Freq.     Percent        Cum.
------------+-----------------------------------
       2013 |      7,874       78.74       78.74
       2014 |      1,354       13.54       92.28
       9999 |        772        7.72      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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