Frequencies for first 10,000 rows of rfid variable in nhamcsed2013 dataset :

Does ED use |
      radio |
  frequency |
identificat |
        ion |
  tracking? |      Freq.     Percent        Cum.
------------+-----------------------------------
      Blank |         98        0.98        0.98
    Unknown |        935        9.35       10.33
        Yes |      2,214       22.14       32.47
         No |      6,753       67.53      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 7 Nov 2016