Year	Percent
1990	54.935
1991	54.643
1992	54.367
1993	54.099
1994	53.856
1995	53.662
1996	53.524
1997	54.272
1998	52.814
1999	52.045
2000	52.612
2001	51.999
2002	50.955
2003	52.317
2004	53.215
2005	53.498
2006	54.728
2007	54.15
2008	54.888
2009	54.739
2010	55.025
2011	55.56
2012	55.361
2013	55.338
2014	54.591
2015	55.99
2016	56.473
2017	56.363
2018	56.206
2019	56.016
2020	55.803
2021	55.575
2022	55.333
2023	55.098
2024	54.898
2025	54.752
2026	54.671
2027	54.662
2028	54.7
2029	54.746
2030	54.775