Frequencies for first 10,000 rows of mpre6 variable in natl1985 dataset :

      Month |
   Prenatal |
 Care began |
   Recode 6 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,931       49.31       49.31
          2 |      2,304       23.04       72.35
          3 |      2,037       20.37       92.72
          4 |        491        4.91       97.63
          5 |        158        1.58       99.21
          6 |         79        0.79      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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