Frequencies for first 10,000 rows of lmpmon variable in natlterr1999 dataset :

 Month Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          3 |        406        4.06        4.06
          4 |      3,758       37.58       41.64
          5 |      4,076       40.76       82.40
          6 |      1,343       13.43       95.83
          7 |        157        1.57       97.40
          8 |         49        0.49       97.89
          9 |          7        0.07       97.96
         99 |        204        2.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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