Frequencies for first 10,000 rows of rept_cod_num variable in demo2009q1 dataset :

          rept_cod_num |      Freq.     Percent        Cum.
-----------------------+-----------------------------------
            DIR Direct |      1,030       10.30       10.30
EXP Expedited (15-Day) |      7,232       72.32       82.62
          PER Periodic |      1,738       17.38      100.00
-----------------------+-----------------------------------
                 Total |     10,000      100.00

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