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

    AIR BAG |
AVAILABILIT |
          Y |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        834        8.34        8.34
          3 |        101        1.01        9.35
          4 |         14        0.14        9.49
          9 |      9,051       90.51      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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