Frequencies for first 10,000 rows of rept_cod_num variable in demo2007q2 dataset :

          rept_cod_num |      Freq.     Percent        Cum.
-----------------------+-----------------------------------
            DIR Direct |        920        9.20        9.20
EXP Expedited (15-Day) |      8,977       89.77       98.97
          PER Periodic |        103        1.03      100.00
-----------------------+-----------------------------------
                 Total |     10,000      100.00

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