Frequencies for first 10,000 rows of prov2420 variable in pos2002 dataset :

       srv: |
psychologic |
         al |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,893       98.93       98.93
          0 |         53        0.53       99.46
          1 |         12        0.12       99.58
          2 |         22        0.22       99.80
          3 |         20        0.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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