Frequencies for first 10,000 rows of exp_dt_num variable in drug2011q3 dataset :

 Expiration |
date of the |
      drug. |
 (YYYYMMDD) |      Freq.     Percent        Cum.
------------+-----------------------------------
  31aug2011 |          1        0.01        0.01
  01oct2011 |          1        0.01        0.02
  20dec2011 |          1        0.01        0.03
  01jan2012 |          1        0.01        0.04
  01mar2012 |          1        0.01        0.05
  01jul2012 |          1        0.01        0.06
  31oct2012 |          1        0.01        0.07
  31dec2012 |          1        0.01        0.08
          . |      9,992       99.92      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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