Frequencies for first 10,000 rows of cardmon variable in nhamcsed2009 dataset :

    cardiac |
    monitor |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,120       91.20       91.20
          1 |        880        8.80      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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