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

    AIR BAG |
AVAILABILIT |
 Y/FUNCTION |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        631        6.31        6.31
          1 |      1,448       14.48       20.79
          2 |          3        0.03       20.82
          8 |          3        0.03       20.85
          9 |         32        0.32       21.17
         20 |        667        6.67       27.84
         28 |          2        0.02       27.86
         29 |      1,833       18.33       46.19
         30 |      5,038       50.38       96.57
         31 |          3        0.03       96.60
         32 |          5        0.05       96.65
         99 |        335        3.35      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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