Year	Percent
1991	0.828
1992	1.818
1993	2.239
1994	3.052
1995	2.295
1996	3.1398
1997	3.9869
1998	2.8352
1999	2.203
2000	1.5745
2001	0.9975
2002	2.1836
2003	3.3466
2004	3.4744
2005	3.1731
2006	2.7297
2007	2.3013
2008	2.2448
2009	3.2907
2010	4.2072
2011	3.7184
2012	3.8203
2013	4.2943
2014	4.4522
2015	4.1319
2016	4.5348
2017	4.2565