Year	Percent
1990	38.505
1991	39.113
1992	39.423
1993	40.382
1994	42.107
1995	43.465
1996	43.084
1997	46.795
1998	48.776
1999	49.514
2000	47.674
2001	52.162
2002	53.113
2003	52.476
2004	53.001
2005	56.992
2006	56.793
2007	58.143
2008	59.648
2009	60.648
2010	58.39
2011	60.615
2012	60.324
2013	62.044
2014	64.869
2015	64.342
2016	60.887
2017	61.409
2018	61.933
2019	62.461
2020	62.99
2021	63.52
2022	64.048
2023	64.57
2024	65.077
2025	65.569
2026	66.048
2027	66.513
2028	66.972
2029	67.428
2030	67.887