Year	Percent
1990	48.359
1991	50.429
1992	48.694
1993	49.136
1994	49.531
1995	49.255
1996	49.885
1997	50.877
1998	51.788
1999	52.123
2000	52.631
2001	53.4
2002	53.985
2003	54.672
2004	54.236
2005	55.284
2006	55.573
2007	56.005
2008	55.868
2009	55.633
2010	55.814
2011	54.613
2012	54.652
2013	54.128
2014	53.798
2015	53.777
2016	53.575
2017	53.312
2018	53.04
2019	52.752
2020	52.44
2021	52.155
2022	51.862
2023	51.56
2024	51.248
2025	50.926
2026	50.625
2027	50.323
2028	50.016
2029	49.697
2030	49.357