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

   srv: ekg |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,666       96.66       96.66
          0 |         21        0.21       96.87
          1 |        116        1.16       98.03
          2 |        187        1.87       99.90
          3 |         10        0.10      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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