Year	Percent
1991	1.9312
1992	1.91026
1993	1.88596
1994	1.85908
1995	1.82897
1996	1.79629
1997	1.75648
1998	1.72057
1999	1.68002
2000	1.6287
2001	1.5258
2002	1.5426
2003	1.5036
2004	1.4662
2005	1.4072
2006	1.3891
2007	1.2926
2008	1.3372
2009	1.35
2010	1.423
2011	1.4448
2012	1.3805
2013	1.3171
2014	1.3474
2015	1.4369
2016	1.4298
2017	1.4271
2018	1.3694
2019	1.35505