Year	Percent
1990	5.6
1997	2
1999	1.3
2000	1.1
2001	1.9
2002	1.7
2004	3.1
2005	2
2006	2.3
2007	2.9
2008	3.2
2009	3.2
2011	3.8
2012	3.4
2013	3.6
2014	3.8
2015	3.9
2016	3.9