Frequencies for first 10,000 rows of repeac variable in natl1990 dataset :

     Repeat |
  C-section |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        841        8.41        8.41
          2 |      9,152       91.52       99.93
          9 |          7        0.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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