Frequencies for first 10,000 rows of rept_cod_num variable in demo2012q1 dataset :

          rept_cod_num |      Freq.     Percent        Cum.
-----------------------+-----------------------------------
            DIR Direct |        383        3.83        3.83
EXP Expedited (15-Day) |      7,435       74.35       78.18
          PER Periodic |      2,182       21.82      100.00
-----------------------+-----------------------------------
                 Total |     10,000      100.00

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