Frequencies for first 10,000 rows of lmpmon variable in natlterr1997 dataset :

 Month Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          2 |          3        0.03        0.03
          3 |        585        5.85        5.88
          4 |      4,218       42.18       48.06
          5 |      4,252       42.52       90.58
          6 |        671        6.71       97.29
          7 |        106        1.06       98.35
          8 |         32        0.32       98.67
          9 |          4        0.04       98.71
         99 |        129        1.29      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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