Frequencies for first 10,000 rows of lmpmon variable in natl1986 dataset :

 Month Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         28        0.28        0.28
          2 |         94        0.94        1.22
          3 |      1,099       10.99       12.21
          4 |      3,611       36.11       48.32
          5 |      3,172       31.72       80.04
          6 |      1,371       13.71       93.75
          7 |        233        2.33       96.08
          8 |         49        0.49       96.57
          9 |         28        0.28       96.85
         10 |         12        0.12       96.97
         11 |          8        0.08       97.05
         12 |          6        0.06       97.11
         99 |        289        2.89      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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