Year	Percent
1997	2.13127
1998	1.84449
1999	1.85421
2000	2.18202
2001	2.01072
2002	2.60047
2003	2.11144
2004	1.93905
2005	1.68414
2006	1.76779
2007	1.47787
2008	1.06146
2009	1.23084
2010	1.24804
2011	1.4374
2012	1.44175
2013	1.51831
2014	1.43783
2015	1.41223
2016	1.21921
2017	0.86733