Frequencies for first 10,000 rows of mpre6 variable in natl1979 dataset :

      Month |
   Prenatal |
 Care began |
   Recode 6 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,768       47.68       47.68
          2 |      2,191       21.91       69.59
          3 |      2,284       22.84       92.43
          4 |        556        5.56       97.99
          5 |        116        1.16       99.15
          6 |         85        0.85      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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