Frequencies for first 10,000 rows of extricat variable in person dataset :

extrication |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,346       93.46       93.46
          1 |        467        4.67       98.13
          9 |        187        1.87      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016