Frequencies for seat_pos variable in person dataset :

    SEATING |
   POSITION |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        140       17.16       17.16
         11 |        474       58.09       75.25
         12 |          1        0.12       75.37
         13 |         98       12.01       87.38
         18 |          1        0.12       87.50
         19 |          1        0.12       87.62
         21 |         42        5.15       92.77
         22 |          8        0.98       93.75
         23 |         22        2.70       96.45
         28 |          2        0.25       96.69
         29 |          1        0.12       96.81
         31 |          2        0.25       97.06
         32 |          2        0.25       97.30
         33 |          2        0.25       97.55
         38 |          1        0.12       97.67
         39 |          1        0.12       97.79
         49 |          1        0.12       97.92
         51 |         14        1.72       99.63
         52 |          3        0.37      100.00
------------+-----------------------------------
      Total |        816      100.00

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