Frequencies for first 10,000 rows of rept_cod_num variable in demo2005q2 dataset :

          rept_cod_num |      Freq.     Percent        Cum.
-----------------------+-----------------------------------
            DIR Direct |        624        6.24        6.24
EXP Expedited (15-Day) |      4,540       45.40       51.64
          PER Periodic |      4,836       48.36      100.00
-----------------------+-----------------------------------
                 Total |     10,000      100.00

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