Year	Percent
1997	5.1843
1998	5.7681
1999	6.8603
2000	7.49
2001	7.044
2002	8.5505
2003	7.4272
2004	9.0218
2005	7.7843
2006	8.2192
2007	7.2289
2008	6.6808
2009	7.6708
2010	7.5659
2011	7.7415
2012	7.3544
2013	7.7072
2014	7.3469
2015	7.5315
2016	6.5875
2017	5.6024