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

    AIR BAG |
   DEPLOYED |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |      4,105       41.05       41.05
          1 |      1,728       17.28       58.33
          2 |         94        0.94       59.27
          3 |          7        0.07       59.34
          8 |         97        0.97       60.31
          9 |        896        8.96       69.27
         20 |      2,515       25.15       94.42
         28 |          3        0.03       94.45
         99 |        555        5.55      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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