Frequencies for first 10,000 rows of rept_cod_num variable in demo2006q4 dataset :

          rept_cod_num |      Freq.     Percent        Cum.
-----------------------+-----------------------------------
            DIR Direct |        980        9.80        9.80
EXP Expedited (15-Day) |      8,520       85.20       95.00
          PER Periodic |        500        5.00      100.00
-----------------------+-----------------------------------
                 Total |     10,000      100.00

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