Frequencies for first 10,000 rows of injury variable in nhamcsopd1996 dataset :

   is visit |
 related to |
  injury or |
 poisoning? |      Freq.     Percent        Cum.
------------+-----------------------------------
        Yes |        959        9.59        9.59
         No |      9,041       90.41      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 28 Mar 2016