Frequencies for first 10,000 rows of injury variable in nhamcsed2001 dataset :

   is visit |
 related to |
injury/pois |
on/adv eff? |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      6,310       63.10       63.10
          1 |      3,690       36.90      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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