Frequencies for first 10,000 rows of uop_tocol variable in natl2011 dataset :

  Tocolysis |
        U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |         79        0.79        0.79
          2 |      8,265       82.65       83.44
          9 |      1,656       16.56      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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