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

       FIRE |
 OCCURRENCE |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      9,008       90.08       90.08
          1 |        310        3.10       93.18
          . |        682        6.82      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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