Year	Percent
1990	1.754
1991	2.098
1992	2.878
1993	4.428
1994	5.204
1995	7.9325
1996	7.4409
1997	8.2637
1998	5.4759
1999	6.0425
2000	4.5795
2001	3.9249
2002	3.9098
2003	3.5414
2004	4.0529
2005	3.4484
2006	3.8179
2007	3.5226
2008	3.4182
2009	4.5873
2010	4.8181
2011	4.4717
2012	4.6109
2013	4.2223
2014	4.5399
2015	4.5681
2016	4.3786
2017	4.3758