Frequencies for first 10,000 rows of lastyear variable in nda2segments dataset :

  Last Year |
NDC Appears |
   in State |
       Drug |
 Utilzation |
       Data |      Freq.     Percent        Cum.
------------+-----------------------------------
       1991 |      1,579       15.79       15.79
       1992 |      1,703       17.03       32.82
       1993 |        768        7.68       40.50
       1994 |        233        2.33       42.83
       1995 |        228        2.28       45.11
       1996 |        240        2.40       47.51
       1997 |        219        2.19       49.70
       1998 |        290        2.90       52.60
       1999 |        256        2.56       55.16
       2000 |        180        1.80       56.96
       2001 |        192        1.92       58.88
       2002 |        218        2.18       61.06
       2003 |        257        2.57       63.63
       2004 |        237        2.37       66.00
       2005 |        277        2.77       68.77
       2006 |        221        2.21       70.98
       2007 |        187        1.87       72.85
       2008 |        191        1.91       74.76
       2009 |        181        1.81       76.57
       2010 |        219        2.19       78.76
       2011 |        211        2.11       80.87
       2012 |        191        1.91       82.78
       2013 |        270        2.70       85.48
       2014 |        198        1.98       87.46
       2015 |        253        2.53       89.99
       2016 |        195        1.95       91.94
       2017 |        806        8.06      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 20 Feb 2018