Frequencies for first 10,000 rows of dlmp_yy variable in natl2005 dataset :

Last Normal |
   Menses - |
   Year U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
       2003 |         14        0.14        0.14
       2004 |      7,574       75.74       75.88
       2005 |      2,142       21.42       97.30
       9999 |        270        2.70      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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