Frequencies for first 10,000 rows of exp_dt variable in drug2006q2 dataset :

 Expiration |
date of the |
      drug. |
  (YYYYMMDD |
    format) |      Freq.     Percent        Cum.
------------+-----------------------------------
   2.00e+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 |          2        0.02        0.10
   2.01e+07 |          1        0.01        0.11
   2.01e+07 |          1        0.01        0.12
   2.01e+07 |          1        0.01        0.13
   2.01e+07 |          1        0.01        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 |          2        0.02        0.19
   2.01e+07 |          2        0.02        0.21
   2.01e+07 |          5        0.05        0.26
   2.01e+07 |          1        0.01        0.27
   2.01e+07 |          1        0.01        0.28
   2.01e+07 |          2        0.02        0.30
   2.01e+07 |          1        0.01        0.31
   2.01e+07 |          1        0.01        0.32
   2.01e+07 |          1        0.01        0.33
   2.01e+07 |          1        0.01        0.34
   2.01e+07 |          1        0.01        0.35
   2.01e+07 |          1        0.01        0.36
   2.01e+07 |          1        0.01        0.37
   2.01e+07 |          1        0.01        0.38
   2.01e+07 |          1        0.01        0.39
   2.01e+07 |          1        0.01        0.40
   2.01e+07 |          1        0.01        0.41
   2.01e+07 |          2        0.02        0.43
          . |      9,957       99.57      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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