Frequencies for first 10,000 rows of rept_cod_num variable in demo2006q1 dataset :

          rept_cod_num |      Freq.     Percent        Cum.
-----------------------+-----------------------------------
            DIR Direct |        909        9.09        9.09
EXP Expedited (15-Day) |      8,722       87.22       96.31
          PER Periodic |        369        3.69      100.00
-----------------------+-----------------------------------
                 Total |     10,000      100.00

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