Year	Percent
1991	4.24989
1992	4.16575
1993	4.07727
1994	3.98574
1995	3.82888
1996	3.78052
1997	3.70561
1998	3.48966
1999	3.21088
2000	3.28293
2001	3.12209
2002	2.93633
2003	3.04056
2004	3.31304
2005	3.70137
2006	3.64759
2007	3.33513
2008	3.16513
2009	3.13101
2010	3.06173
2011	2.78382
2012	2.73263
2013	2.09528
2014	2.29217
2015	2.31968
2016	2.26232
2017	2.2682
2018	2.09824
2019	2.07718