Frequencies for first 10,000 rows of lmpmon variable in natl1990 dataset :

 Month Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         18        0.18        0.18
          2 |         78        0.78        0.96
          3 |        980        9.80       10.76
          4 |      3,478       34.78       45.54
          5 |      3,430       34.30       79.84
          6 |      1,393       13.93       93.77
          7 |        206        2.06       95.83
          8 |         65        0.65       96.48
          9 |         29        0.29       96.77
         10 |         10        0.10       96.87
         11 |         13        0.13       97.00
         12 |         12        0.12       97.12
         99 |        288        2.88      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 3 Jan 2016