Frequencies for first 10,000 rows of lmpmon variable in natl1988 dataset :

 Month Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         26        0.26        0.26
          2 |         81        0.81        1.07
          3 |      1,025       10.25       11.32
          4 |      3,392       33.92       45.24
          5 |      3,179       31.79       77.03
          6 |      1,578       15.78       92.81
          7 |        309        3.09       95.90
          8 |         80        0.80       96.70
          9 |         37        0.37       97.07
         10 |         14        0.14       97.21
         11 |         10        0.10       97.31
         12 |          9        0.09       97.40
         99 |        260        2.60      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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