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

extrication |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,964       89.64       89.64
          1 |        824        8.24       97.88
          9 |        212        2.12      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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