Frequencies for first 10,000 rows of rfid variable in nhamcsed2012 dataset :

Does ED use |
      radio |
  frequency |
identificat |
        ion |
  tracking? |      Freq.     Percent        Cum.
------------+-----------------------------------
      Blank |        152        1.52        1.52
    Unknown |        819        8.19        9.71
        Yes |      1,209       12.09       21.80
         No |      7,820       78.20      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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