Frequencies for first 10,000 rows of rept_cod_num variable in demo2005q3 dataset :

          rept_cod_num |      Freq.     Percent        Cum.
-----------------------+-----------------------------------
            DIR Direct |        900        9.00        9.00
EXP Expedited (15-Day) |      8,475       84.75       93.75
          PER Periodic |        625        6.25      100.00
-----------------------+-----------------------------------
                 Total |     10,000      100.00

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