Frequencies for first 10,000 rows of pgm_prtcptn_cd variable in pos2000 dataset :

    program |
participati |
         on |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      3,906       39.06       39.06
          0 |         80        0.80       39.86
          1 |        550        5.50       45.36
          2 |      1,962       19.62       64.98
          3 |      3,502       35.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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