Frequencies for first 10,000 rows of dlmp_yy variable in natlterr2011 dataset :

Last Normal |
   Menses - |
   Year U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
       2009 |          6        0.06        0.06
       2010 |      6,380       63.80       63.86
       2011 |        538        5.38       69.24
       9999 |      3,076       30.76      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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