Frequencies for first 10,000 rows of ekg_srvc_cd variable in pos2008 dataset :

   srv: ekg |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,650       96.50       96.50
          0 |         23        0.23       96.73
          1 |        117        1.17       97.90
          2 |        196        1.96       99.86
          3 |         14        0.14      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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