Year | |
---|---|
1992 | 3.5 |
1993 | 3.6 |
1994 | 3.5 |
1995 | 3.1 |
1996 | 3.6 |
1997 | 3.3 |
1998 | 3.6 |
1999 | 4.0 |
2000 | 3.9 |
2001 | 4.0 |
2002 | 4.1 |
2003 | 4.7 |
2004 | 3.5 |
2005 | 3.4 |
2006 | 4.2 |
2007 | 4.0 |
2008 | 4.6 |
2009 | 4.3 |
2010 | 4.3 |
2011 | 4.3 |
2012 | 4.6 |
2013 | 4.8 |
2014 | 4.9 |
2015 | 5.1 |