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

extrication |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      8,969       89.69       89.69
          1 |        656        6.56       96.25
          9 |        375        3.75      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 22 Oct 2016