Frequencies for first 10,000 rows of rept_cod_num variable in demo2005q4 dataset :

          rept_cod_num |      Freq.     Percent        Cum.
-----------------------+-----------------------------------
            DIR Direct |        817        8.17        8.17
EXP Expedited (15-Day) |      8,684       86.84       95.01
          PER Periodic |        499        4.99      100.00
-----------------------+-----------------------------------
                 Total |     10,000      100.00

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