Frequencies for first 10,000 rows of lmpyr variable in natl2001 dataset :

  Year Last |
     Normal |
     Menses |
      Began |      Freq.     Percent        Cum.
------------+-----------------------------------
       2000 |      9,628       96.28       96.28
       2001 |          5        0.05       96.33
       9999 |        367        3.67      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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