Frequencies for first 10,000 rows of induct variable in natl2001 dataset :

  Induction |
   of labor |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      2,640       26.40       26.40
          2 |      7,358       73.58       99.98
          8 |          1        0.01       99.99
          9 |          1        0.01      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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