Frequencies for first 10,000 rows of exp_dt_num variable in drug2006q3 dataset : Expiration | date of the | drug. | (YYYYMMDD) | Freq. Percent Cum. ------------+----------------------------------- 01jun2004 | 1 0.01 0.01 15mar2005 | 1 0.01 0.02 01nov2005 | 2 0.02 0.04 31dec2005 | 2 0.02 0.06 31mar2006 | 1 0.01 0.07 31oct2006 | 1 0.01 0.08 30nov2006 | 1 0.01 0.09 31dec2006 | 2 0.02 0.11 06feb2007 | 1 0.01 0.12 23mar2007 | 1 0.01 0.13 31mar2007 | 1 0.01 0.14 30apr2007 | 1 0.01 0.15 01may2007 | 2 0.02 0.17 01jun2007 | 4 0.04 0.21 02jun2007 | 1 0.01 0.22 27jun2007 | 1 0.01 0.23 01jul2007 | 1 0.01 0.24 17jul2007 | 1 0.01 0.25 01aug2007 | 5 0.05 0.30 21aug2007 | 1 0.01 0.31 01sep2007 | 2 0.02 0.33 01oct2007 | 8 0.08 0.41 04nov2007 | 1 0.01 0.42 30nov2007 | 1 0.01 0.43 01jan2008 | 3 0.03 0.46 31jan2008 | 2 0.02 0.48 01feb2008 | 1 0.01 0.49 28feb2008 | 1 0.01 0.50 01mar2008 | 1 0.01 0.51 01may2008 | 1 0.01 0.52 31oct2008 | 1 0.01 0.53 01dec2008 | 1 0.01 0.54 31jan2009 | 1 0.01 0.55 02mar2009 | 1 0.01 0.56 13mar2009 | 1 0.01 0.57 31mar2009 | 1 0.01 0.58 30apr2009 | 1 0.01 0.59 20dec2010 | 1 0.01 0.60 . | 9,940 99.40 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 18 Dec 2015