Frequencies for first 10,000 rows of lmpmon variable in natl1989 dataset :

 Month Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         29        0.29        0.29
          2 |         91        0.91        1.20
          3 |      1,029       10.29       11.49
          4 |      3,682       36.82       48.31
          5 |      3,301       33.01       81.32
          6 |      1,180       11.80       93.12
          7 |        196        1.96       95.08
          8 |         56        0.56       95.64
          9 |         28        0.28       95.92
         10 |         15        0.15       96.07
         11 |          7        0.07       96.14
         12 |          4        0.04       96.18
         99 |        382        3.82      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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