Frequencies for first 10,000 rows of seen72 variable in nhamcsed2014 dataset :

Was patient |
    seen in |
    this ED |
 within the |
    last 72 |
  hours and |
discharged? |      Freq.     Percent        Cum.
------------+-----------------------------------
      Blank |         96        0.96        0.96
    Unknown |        932        9.32       10.28
        Yes |        330        3.30       13.58
         No |      8,642       86.42      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 11 Apr 2017