Frequencies for first 10,000 rows of mpre6 variable in natl1997 dataset :

      Month |
   Prenatal |
 Care Began |
   Recode 6 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      6,444       64.44       64.44
          2 |      1,708       17.08       81.52
          3 |      1,414       14.14       95.66
          4 |        296        2.96       98.62
          5 |         88        0.88       99.50
          6 |         50        0.50      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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