Year	Percent
1990	53.018
1991	52.829
1992	52.586
1993	52.598
1994	52.974
1995	52.639
1996	52.361
1997	52.474
1998	52.27
1999	52.55
2000	52.062
2001	51.977
2002	51.796
2003	51.888
2004	51.81
2005	51.47
2006	51.235
2007	51.621
2008	51.482
2009	51.181
2010	50.742
2011	50.945
2012	51.042
2013	51.102
2014	50.871
2015	50.903
2016	51.282
2017	51.179
2018	51.076
2019	50.972
2020	50.869
2021	50.766
2022	50.662
2023	50.559
2024	50.456
2025	50.352
2026	50.249
2027	50.145
2028	50.042
2029	49.939
2030	49.835