Frequencies for first 10,000 rows of prov2420 variable in pos2004 dataset :

       srv: |
psychologic |
         al |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,869       98.69       98.69
          0 |         76        0.76       99.45
          1 |         13        0.13       99.58
          2 |         21        0.21       99.79
          3 |         21        0.21      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 26 Jan 2016