Frequencies for first 10,000 rows of pgm_prtcptn_cd variable in pos1994 dataset :

    program |
participati |
         on |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      4,428       44.28       44.28
          0 |        105        1.05       45.33
          1 |        521        5.21       50.54
          2 |      1,843       18.43       68.97
          3 |      3,103       31.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 17 May 2017