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

    SEATING |
   POSITION |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        665        6.65        6.65
         11 |      5,658       56.58       63.23
         12 |         52        0.52       63.75
         13 |      1,693       16.93       80.68
         18 |          2        0.02       80.70
         19 |          3        0.03       80.73
         21 |        497        4.97       85.70
         22 |        206        2.06       87.76
         23 |        513        5.13       92.89
         28 |         17        0.17       93.06
         29 |         27        0.27       93.33
         31 |         28        0.28       93.61
         32 |         17        0.17       93.78
         33 |         27        0.27       94.05
         38 |          2        0.02       94.07
         39 |         10        0.10       94.17
         41 |          2        0.02       94.19
         42 |          2        0.02       94.21
         43 |          2        0.02       94.23
         49 |          2        0.02       94.25
         50 |         22        0.22       94.47
         51 |        225        2.25       96.72
         52 |         18        0.18       96.90
         54 |          1        0.01       96.91
         55 |          6        0.06       96.97
         99 |        303        3.03      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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