Frequencies for first 10,000 rows of lmpmon variable in natl1997 dataset :

 Month Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          9        0.09        0.09
          2 |         61        0.61        0.70
          3 |        824        8.24        8.94
          4 |      3,698       36.98       45.92
          5 |      3,793       37.93       83.85
          6 |      1,029       10.29       94.14
          7 |        137        1.37       95.51
          8 |         69        0.69       96.20
          9 |         29        0.29       96.49
         10 |         17        0.17       96.66
         11 |          7        0.07       96.73
         12 |          9        0.09       96.82
         99 |        318        3.18      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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