Frequencies for first 10,000 rows of exp_dt variable in drug2009q4 dataset :

 Expiration |
date of the |
      drug. |
  (YYYYMMDD |
    format) |      Freq.     Percent        Cum.
------------+-----------------------------------
   2.01e+07 |          1        0.01        0.01
   2.01e+07 |          1        0.01        0.02
   2.01e+07 |          1        0.01        0.03
   2.01e+07 |          1        0.01        0.04
   2.01e+07 |          1        0.01        0.05
   2.01e+07 |          1        0.01        0.06
   2.01e+07 |          1        0.01        0.07
   2.01e+07 |          1        0.01        0.08
   2.01e+07 |          1        0.01        0.09
   2.01e+07 |          1        0.01        0.10
   2.01e+07 |          4        0.04        0.14
   2.01e+07 |          1        0.01        0.15
   2.01e+07 |          1        0.01        0.16
   2.01e+07 |          1        0.01        0.17
   2.01e+07 |          1        0.01        0.18
   2.01e+07 |          1        0.01        0.19
   2.01e+07 |          1        0.01        0.20
   2.01e+07 |          1        0.01        0.21
   2.01e+07 |          1        0.01        0.22
   2.01e+07 |          1        0.01        0.23
   2.01e+07 |          1        0.01        0.24
          . |      9,976       99.76      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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