Frequencies for first 10,000 rows of uop_tocol variable in natlterr2010 dataset :

  Tocolysis |
        U;R |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |        128        1.28        1.28
          2 |      7,595       75.95       77.23
          9 |      2,277       22.77      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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