Frequencies for first 10,000 rows of foll_seq variable in demo2012q2 dataset :

        The |
   sequence |
number of a |
   followup |
     report |      Freq.     Percent        Cum.
------------+-----------------------------------
          1 |          1        0.01        0.01
          3 |          3        0.03        0.04
          4 |          2        0.02        0.06
          . |      9,994       99.94      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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