Frequencies for first 10,000 rows of cardmon variable in nhamcsed1997 dataset :

    cardiac |
    monitor |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,166       91.66       91.66
          1 |        834        8.34      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016