Frequencies for first 10,000 rows of injury72 variable in namcs2014 dataset :

         Did the injury or |
 poisoning occur within 72 |
   hours prior to the date |
              and time of  |      Freq.     Percent        Cum.
---------------------------+-----------------------------------
                     Blank |      9,503       95.03       95.03
                   Unknown |         37        0.37       95.40
                       Yes |         82        0.82       96.22
                        No |        352        3.52       99.74
Questionable injury status |         26        0.26      100.00
---------------------------+-----------------------------------
                     Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 27 Mar 2017