Year	Percent
1990	3.984
1991	3.479
1992	3.707
1993	3.482
1994	3.019
1995	3.327
1996	2.13
1997	1.842
1998	2.404
1999	2.838
2000	2.86
2001	3.051
2002	4.581
2003	4.964
2004	4.772
2005	5.134
2006	4.6187
2007	4.4402
2008	5.6036
2009	7.2826
2010	6.5259
2011	5.5084
2012	4.7825
2013	5.6545
2014	7.3613
2015	7.9149
2016	7.335
2017	7.7035