Frequencies for first 10,000 rows of exp_dt variable in drug2018q1 dataset :

 Expiration |
date of the |
drug.Multip |
   le dates |
  possible. |      Freq.     Percent        Cum.
------------+-----------------------------------
          . |     10,000      100.00      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 19 Jun 2018