Frequencies for first 10,000 rows of lmpmon variable in natl1983 dataset :

 Month Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         26        0.26        0.26
          2 |         99        0.99        1.25
          3 |      1,167       11.67       12.92
          4 |      3,730       37.30       50.22
          5 |      3,323       33.23       83.45
          6 |      1,174       11.74       95.19
          7 |        221        2.21       97.40
          8 |         67        0.67       98.07
          9 |         29        0.29       98.36
         10 |         12        0.12       98.48
         11 |          3        0.03       98.51
         12 |          2        0.02       98.53
         99 |        147        1.47      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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