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

    SEATING |
   POSITION |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        628        6.28        6.28
         11 |      5,668       56.68       62.96
         12 |         87        0.87       63.83
         13 |      1,786       17.86       81.69
         19 |          1        0.01       81.70
         21 |        517        5.17       86.87
         22 |        233        2.33       89.20
         23 |        568        5.68       94.88
         28 |          4        0.04       94.92
         29 |          6        0.06       94.98
         31 |         33        0.33       95.31
         32 |         19        0.19       95.50
         33 |         27        0.27       95.77
         38 |          1        0.01       95.78
         39 |          3        0.03       95.81
         50 |         19        0.19       96.00
         51 |        160        1.60       97.60
         52 |         34        0.34       97.94
         53 |          1        0.01       97.95
         54 |          1        0.01       97.96
         55 |          5        0.05       98.01
         99 |        199        1.99      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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