Year	Percent
1990	62.946
1991	63.042
1992	62.944
1993	60.783
1994	59.143
1995	59.378
1996	57.622
1997	56.903
1998	56.803
1999	57.673
2000	57.932
2001	57.703
2002	57.456
2003	58.145
2004	57.755
2005	58.378
2006	58.944
2007	58.876
2008	58.35
2009	58.169
2010	58.156
2011	58.546
2012	59.271
2013	60.169
2014	61.981
2015	63.38
2016	64.568
2017	64.215
2018	63.87
2019	63.561
2020	63.299
2021	62.981
2022	62.698
2023	62.451
2024	62.243
2025	62.076
2026	61.862
2027	61.691
2028	61.542
2029	61.38
2030	61.185