Year	Percent
1990	48.024
1991	48.205
1992	48.248
1993	48.139
1994	47.977
1995	47.705
1996	47.549
1997	47.271
1998	47.118
1999	47.335
2000	46.944
2001	46.634
2002	46.281
2003	45.977
2004	45.657
2005	45.415
2006	45.261
2007	45.937
2008	45.23
2009	44.193
2010	42.879
2011	42.636
2012	43.014
2013	43.951
2014	44.428
2015	44.072
2016	46.138
2017	45.85
2018	45.568
2019	45.299
2020	45.046
2021	44.801
2022	44.581
2023	44.379
2024	44.18
2025	43.975
2026	43.763
2027	43.551
2028	43.332
2029	43.099
2030	42.848