Frequencies for first 10,000 rows of ekg_srvc_cd variable in pos2009 dataset :

   SRV: EKG |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,644       96.44       96.44
          0 |         31        0.31       96.75
          1 |        119        1.19       97.94
          2 |        195        1.95       99.89
          3 |         11        0.11      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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