Frequencies for first 10,000 rows of uop_tocol variable in natl2009 dataset :

  Tocolysis |
        U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        167        1.67        1.67
          2 |      9,825       98.25       99.92
          9 |          8        0.08      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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