Frequencies for first 10,000 rows of dlmp_yy variable in natl2016 dataset :

Last Normal |
Menses Year |
  nnnn Year |
    of last |
     normal |
     menses |      Freq.     Percent        Cum.
------------+-----------------------------------
       2015 |      7,924       79.24       79.24
       2016 |      1,503       15.03       94.27
       9999 |        573        5.73      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 4 Oct 2017