Year	Percent
1991	46.434
1992	46.525
1993	46.623
1994	46.691
1995	46.731
1996	46.735
1997	46.702
1998	46.635
1999	46.551
2000	46.443
2001	46.326
2002	46.184
2003	46.041
2004	45.922
2005	45.84
2006	45.803
2007	45.807
2008	45.834
2009	45.855
2010	45.844
2011	45.817
2012	45.76
2013	45.707
2014	45.703
2015	45.762
2016	45.907
2017	46.1
2018	46.321
2019	46.489
2020	46.583
2021	46.618
2022	46.587