Frequencies for first 10,000 rows of rept_cod_num variable in demo2008q1 dataset :

          rept_cod_num |      Freq.     Percent        Cum.
-----------------------+-----------------------------------
            DIR Direct |        827        8.27        8.27
EXP Expedited (15-Day) |      7,538       75.38       83.65
          PER Periodic |      1,635       16.35      100.00
-----------------------+-----------------------------------
                 Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Dec 2015