Frequencies for first 10,000 rows of injury variable in nhamcsopd1997 dataset :

    is this |
      visit |
 related to |
  injury or |
 poisoning? |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,043       90.43       90.43
          1 |        957        9.57      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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