Frequencies for first 10,000 rows of rept_cod_num variable in demo2009q4 dataset :

          rept_cod_num |      Freq.     Percent        Cum.
-----------------------+-----------------------------------
            DIR Direct |        514        5.14        5.14
EXP Expedited (15-Day) |      6,702       67.02       72.16
          PER Periodic |      2,784       27.84      100.00
-----------------------+-----------------------------------
                 Total |     10,000      100.00

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