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

Carburetion |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      4,859       48.59       48.59
          1 |          2        0.02       48.61
          2 |         20        0.20       48.81
          3 |          2        0.02       48.83
          4 |         11        0.11       48.94
          F |      4,973       49.73       98.67
          T |        100        1.00       99.67
          Z |         33        0.33      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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