Year	Percent
1998	3.75091
1999	3.53959
2000	3.82905
2001	4.08289
2002	4.29202
2003	3.76001
2004	2.84904
2005	2.69663
2006	2.79162
2007	2.76757
2008	2.43133
2009	3.13221
2010	3.0325
2011	2.57172
2012	2.8834
2013	4.39974
2014	3.92902
2015	4.31492
2016	4.69404