Frequencies for first 10,000 rows of rept_cod_num variable in demo2006q2 dataset :

          rept_cod_num |      Freq.     Percent        Cum.
-----------------------+-----------------------------------
            DIR Direct |        754        7.54        7.54
EXP Expedited (15-Day) |      9,076       90.76       98.30
          PER Periodic |        170        1.70      100.00
-----------------------+-----------------------------------
                 Total |     10,000      100.00

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