Frequencies for first 10,000 rows of mpre6 variable in natl1976 dataset :

      Month |
   Prenatal |
 Care began |
   Recode 6 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,446       44.46       44.46
          2 |      2,411       24.11       68.57
          3 |      2,386       23.86       92.43
          4 |        539        5.39       97.82
          5 |        122        1.22       99.04
          6 |         96        0.96      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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