Year	Percent
1990	58.256
1991	59.585
1992	61.009
1993	62.539
1994	64.189
1995	63.329
1996	61.123
1997	59.089
1998	58.388
1999	57.76
2000	60.24
2001	60.65
2002	59.48
2003	58.9
2004	57.41
2005	54.8
2006	53.805
2007	52.807
2008	51.807
2009	50.805
2010	49.802
2011	48.8
2012	50.2
2013	51.6
2014	52.1
2015	51.4
2016	54.5
2017	53.885
2018	53.269
2019	52.654
2020	52.038
2021	51.423
2022	50.807
2023	50.192
2024	49.576
2025	48.961
2026	48.346
2027	47.73
2028	47.115
2029	46.499
2030	45.884