Year	Percent
1990	46.328
1991	46.427
1992	46.771
1993	47.197
1994	47.376
1995	47.729
1996	48.155
1997	47.777
1998	48.115
1999	48.513
2000	48.605
2001	48.347
2002	48.567
2003	49.81
2004	49.693
2005	50.117
2006	50.157
2007	50.505
2008	50.685
2009	50.97
2010	50.923
2011	50.775
2012	50.931
2013	51.081
2014	50.887
2015	50.729
2016	50.675
2017	50.564
2018	50.472
2019	50.39
2020	50.3
2021	50.226
2022	50.163
2023	50.101
2024	50.033
2025	49.961
2026	49.926
2027	49.899
2028	49.877
2029	49.852
2030	49.816