Frequencies for first 10,000 rows of lmpyr variable in natl1976 dataset :

  Year Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
          - |        197        1.97        1.97
          5 |      9,766       97.66       99.63
          6 |         37        0.37      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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