Frequencies for first 10,000 rows of lmpyr variable in natl1990 dataset :

  Year Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
       1989 |      9,672       96.72       96.72
       1990 |          2        0.02       96.74
       9999 |        326        3.26      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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