Frequencies for first 10,000 rows of foll_seq variable in demo2011q3 dataset :

        The |
   sequence |
number of a |
   followup |
     report |      Freq.     Percent        Cum.
------------+-----------------------------------
            |      9,996       99.96       99.96
          1 |          2        0.02       99.98
          2 |          2        0.02      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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