Year	Percent
1998	5.09822
1999	3.95868
2000	5.23925
2001	5.85963
2002	4.5908
2003	4.11913
2004	3.80195
2005	2.73295
2006	1.63262
2007	0.95381
2008	1.02298
2009	3.14439
2010	5.73969
2011	5.36947
2012	4.43321
2013	3.57255
2014	3.39316
2015	2.7966
2016	2.28559
2017	1.94079