Frequencies for first 10,000 rows of mpre6 variable in natl1993 dataset :

      Month |
   Prenatal |
 Care Began |
   Recode 6 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      5,873       58.73       58.73
          2 |      1,960       19.60       78.33
          3 |      1,744       17.44       95.77
          4 |        305        3.05       98.82
          5 |         98        0.98       99.80
          6 |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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