Frequencies for first 10,000 rows of exp_dt_num variable in drug2012q2 dataset :

 Expiration |
date of the |
      drug. |
 (YYYYMMDD) |      Freq.     Percent        Cum.
------------+-----------------------------------
  01jun2011 |          2        0.02        0.02
  14jan2012 |          1        0.01        0.03
  06feb2012 |          1        0.01        0.04
  31mar2012 |          1        0.01        0.05
  28apr2012 |          1        0.01        0.06
  01jun2012 |          1        0.01        0.07
  01jul2012 |          5        0.05        0.12
  31oct2012 |          1        0.01        0.13
  01dec2012 |          1        0.01        0.14
  31dec2012 |          2        0.02        0.16
  12feb2013 |          1        0.01        0.17
  28feb2013 |          1        0.01        0.18
  13mar2013 |          2        0.02        0.20
  20mar2013 |          1        0.01        0.21
  01apr2013 |          1        0.01        0.22
  30apr2013 |          2        0.02        0.24
  31may2013 |          1        0.01        0.25
  01jun2013 |          1        0.01        0.26
  30jun2013 |          1        0.01        0.27
  01jul2013 |          1        0.01        0.28
  31jul2013 |          1        0.01        0.29
  31aug2013 |          3        0.03        0.32
  30sep2013 |          1        0.01        0.33
  30nov2013 |          1        0.01        0.34
  13may2014 |          1        0.01        0.35
  30jun2014 |          1        0.01        0.36
  31jul2014 |          1        0.01        0.37
  31dec2014 |          1        0.01        0.38
  30sep2015 |          1        0.01        0.39
          . |      9,961       99.61      100.00
------------+-----------------------------------
      Total |     10,000      100.00

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