Frequencies for first 10,000 rows of lmpmon variable in natlterr2002 dataset :

 Month Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          3 |        209        2.09        2.09
          4 |      3,257       32.57       34.66
          5 |      4,096       40.96       75.62
          6 |      2,000       20.00       95.62
          7 |        201        2.01       97.63
          8 |         48        0.48       98.11
          9 |         11        0.11       98.22
         99 |        178        1.78      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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