Frequencies for first 10,000 rows of dlmp_yy variable in natl2011 dataset :

Last Normal |
   Menses - |
   Year U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
       2010 |      8,138       81.38       81.38
       2011 |      1,326       13.26       94.64
       9999 |        536        5.36      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015