Frequencies for first 10,000 rows of lmpyr variable in natlterr1995 dataset :

  Year Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
       1994 |      9,841       98.41       98.41
       1995 |          6        0.06       98.47
       9999 |        153        1.53      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Dec 2015