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

    Is visit related to an |
  injury/trauma, overdose, |
     poisoning, or adverse |
                effect of  |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
                     Blank |          6        0.06        0.06
                   Unknown |        662        6.62        6.68
                        No |      5,881       58.81       65.49
                       Yes |      3,437       34.37       99.86
Questionable injury status |         14        0.14      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

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