Frequencies for first 10,000 rows of optmtrc_srvc_cd variable in pos2007 dataset :

       srv: |
 optometric |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      8,682       86.82       86.82
          0 |      1,171       11.71       98.53
          1 |         75        0.75       99.28
          2 |         63        0.63       99.91
          3 |          9        0.09      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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