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

extrication |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,018       90.18       90.18
          1 |        777        7.77       97.95
          9 |        205        2.05      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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