Frequencies for first 10,000 rows of uop_stiml variable in natl2004 dataset :

Stimulation |
 of labor U |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |      1,428       14.28       14.28
          2 |      7,912       79.12       93.40
          9 |        660        6.60      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 21 Jan 2016