Dear all,

I am trying to include observations from 2013 to 2016 in a panel database with observations from 1990 until 2012. This is a sample of the database
Code:
* Example generated by -dataex-. For more info, type help dataex
clear
input int(id year aemp) byte ccaa1
1 1990 1971 16
1 1991 1971  .
1 1992 1971  .
1 1993 1971  .
1 1994 1971 16
1 1995 1971 16
1 1996 1971 16
1 1997 1971 16
1 1998 1971 16
1 1999 1971 16
1 2000 1971 16
1 2001 1971 16
1 2002 1971 16
1 2003 1971 16
1 2004 1971 16
1 2005 1971 16
1 2006 2003 16
1 2007 2003 16
1 2008 2003 16
1 2009 2003 16
1 2010 2003 16
1 2011 2003 16
1 2012 2003 16
2 1990 1965 16
2 1991 1965 16
2 1992 1965 16
2 1993 1965 16
2 1994 1965 16
2 1995 1965 16
2 1996 1965 16
2 1997 1965 16
2 1998 1965 16
2 1999 1965 16
2 2000 1965 16
2 2001 1965 16
2 2002 1965 16
2 2003 1965  .
2 2004 1965  .
2 2005 1965  .
2 2006    .  .
end

I tried the append command. However, the result is that it creates new observations (new id), like if I was adding new subjects when they are the same subjects (id). I just want to add observations for the same subjects for 3 additional years and see these observations following the current year observations. Do you have any suggestions?

I really appreciate any help you can provide.