Frequencies for first 10,000 rows of rept_cod_num variable in demo2009q3 dataset :

          rept_cod_num |      Freq.     Percent        Cum.
-----------------------+-----------------------------------
            DIR Direct |        579        5.79        5.79
EXP Expedited (15-Day) |      8,498       84.98       90.77
          PER Periodic |        923        9.23      100.00
-----------------------+-----------------------------------
                 Total |     10,000      100.00

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