Frequencies for first 10,000 rows of mpre10 variable in natl1983 dataset :

      Month |
   Prenatal |
 Care began |
  Recode 10 |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      4,831       48.31       48.31
          2 |      2,211       22.11       70.42
          3 |      1,089       10.89       81.31
          4 |        699        6.99       88.30
          5 |        426        4.26       92.56
          6 |        262        2.62       95.18
          7 |        176        1.76       96.94
          8 |         72        0.72       97.66
          9 |        180        1.80       99.46
         10 |         54        0.54      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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