Frequencies for first 10,000 rows of induct variable in natl1991 dataset :

  Induction |
   of labor |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        839        8.39        8.39
          2 |      9,149       91.49       99.88
          9 |         12        0.12      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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