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

    AIR BAG |
AVAILABILIT |
          Y |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        797        7.97        7.97
          3 |         36        0.36        8.33
          4 |          1        0.01        8.34
          9 |      9,166       91.66      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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