Year	Percent
1990	44.274
1991	44.246
1992	44.132
1993	44.051
1994	43.987
1995	43.927
1996	43.871
1997	43.876
1998	43.859
1999	43.814
2000	43.699
2001	43.767
2002	43.797
2003	43.726
2004	43.737
2005	43.696
2006	43.79
2007	43.864
2008	43.896
2009	43.902
2010	43.891
2011	44.061
2012	44.221
2013	43.931
2014	44.013
2015	44.1
2016	44.03
2017	44.056
2018	44.082
2019	44.108
2020	44.134
2021	44.16
2022	44.185
2023	44.211
2024	44.237
2025	44.263
2026	44.289
2027	44.314
2028	44.34
2029	44.366
2030	44.392