Year	Percent
1991	10.12035
1992	9.92698
1993	9.73854
1994	9.52834
1995	9.31251
1996	9.08012
1997	8.82593
1998	8.6023
1999	8.32659
2000	7.9753
2001	7.77374
2002	7.76886
2003	7.54875
2004	6.80879
2005	6.14006
2006	5.66638
2007	5.44961
2008	5.32702
2009	5.48481
2010	5.44232
2011	5.25089
2012	5.20087
2013	5.13085
2014	5.12986
2015	5.1284
2016	5.11381
2017	5.06855
2018	5.06635
2019	5.02166