Year	Percent
1991	1.55405
1993	4.85037
1995	3.82623
1996	3.74846
1997	3.41879
1998	2.65428
1999	2.16837
2000	2.28312
2001	2.04392
2002	2.01223
2003	2.04295
2004	1.92894
2005	1.7273
2006	1.52122
2007	1.28889
2008	0.97985
2009	1.26971
2010	1.60312
2011	1.33956
2012	1.33739
2013	1.40971
2014	1.54376
2015	1.76843
2016	1.68477
2017	1.57063