Frequencies for first 10,000 rows of prov2100 variable in pos1991 dataset :

       srv: |
chiropracti |
          c |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,770       87.70       87.70
          0 |      1,205       12.05       99.75
          1 |         10        0.10       99.85
          2 |         11        0.11       99.96
          3 |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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