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

extrication |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,940       89.40       89.40
          1 |        683        6.83       96.23
          9 |        377        3.77      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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