Frequencies for first 10,000 rows of prov2135 variable in pos2004 dataset :

   srv: ekg |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,098       90.98       90.98
          0 |         45        0.45       91.43
          1 |        258        2.58       94.01
          2 |        578        5.78       99.79
          3 |         21        0.21      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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