Frequencies for first 10,000 rows of prov2135 variable in pos1996 dataset :

   srv: ekg |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,497       94.97       94.97
          0 |         33        0.33       95.30
          1 |        139        1.39       96.69
          2 |        327        3.27       99.96
          3 |          4        0.04      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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