Frequencies for first 10,000 rows of uop_tocol variable in natl2008 dataset :

  Tocolysis |
        U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        162        1.62        1.62
          2 |      9,831       98.31       99.93
          9 |          7        0.07      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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