Frequencies for fire_exp variable in vehnit dataset :

       FIRE |
 OCCURRENCE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      1,239       97.41       97.41
          1 |         31        2.44       99.84
          2 |          2        0.16      100.00
------------+-----------------------------------
      Total |      1,272      100.00

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