Frequencies for first 10,000 rows of prev_dwi variable in vehicle dataset :

   Previous |
        DWI |
Convictions |      Freq.     Percent        Cum.
------------+-----------------------------------
         -1 |         15        0.15        0.15
          0 |      9,278       92.78       92.93
          1 |        209        2.09       95.02
          2 |         58        0.58       95.60
          3 |          5        0.05       95.65
          5 |          1        0.01       95.66
         99 |        387        3.87       99.53
          . |         47        0.47      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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