Year	Percent
1990	47.47
1991	47.726
1992	47.951
1993	48.151
1994	48.278
1995	48.339
1996	48.415
1997	48.434
1998	48.322
1999	48.121
2000	47.888
2001	47.688
2002	47.501
2003	47.334
2004	47.22
2005	47.189
2006	47.275
2007	47.377
2008	47.751
2009	48.019
2010	48.2
2011	48.508
2012	48.789
2013	48.644
2014	48.446
2015	48.211
2016	47.964
2017	47.824
2018	47.679
2019	47.537
2020	47.396
2021	47.266
2022	47.133
2023	46.98
2024	46.79
2025	46.555
2026	46.349
2027	46.113
2028	45.862
2029	45.615
2030	45.382