Frequencies for first 10,000 rows of physn_srvc_cd variable in pos2012 dataset 

   Service: |
  Physician |      Freq.     Percent        Cum.
------------+-----------------------------------
          . |      9,191       91.91       91.91
          1 |        509        5.09       97.00
          2 |        220        2.20       99.20
          3 |         80        0.80      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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