Year	Percent
1994	3.90647
1995	4.17266
1996	3.5916
1997	3.64483
1998	3.90459
1999	5.16256
2000	6.74997
2001	7.33144
2002	7.58049
2003	6.96613
2004	7.52886
2005	6.79194
2006	5.74186
2007	4.68059
2008	3.88739
2009	4.32806
2010	5.93826
2011	5.61669
2012	5.76809
2013	5.98358
2014	5.52881
2015	4.49462
2016	3.67419
2017	3.21107