Year	Percent
1990	1.286
1991	2.265
1992	3.654
1993	6.873
1994	8.503
1995	7.4731
1996	9.1518
1997	11.1587
1998	7.7216
1999	7.6907
2000	7.0857
2001	4.9237
2002	4.702
2003	5.3093
2004	5.8573
2005	5.234
2006	4.8693
2007	4.3511
2008	4.065
2009	5.8684
2010	6.636
2011	5.8936
2012	5.7255
2013	5.8421
2014	6.2131
2015	6.0576
2016	6.1377
2017	5.7506