Frequencies for first 10,000 rows of lmpmon variable in natlterr1998 dataset :

 Month Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          3 |        485        4.85        4.85
          4 |      4,094       40.94       45.79
          5 |      4,168       41.68       87.47
          6 |        892        8.92       96.39
          7 |        137        1.37       97.76
          8 |         47        0.47       98.23
          9 |          3        0.03       98.26
         99 |        174        1.74      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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