Year	Percent
1990	43.677
1991	43.886
1992	44.089
1993	44.326
1994	44.567
1995	44.77
1996	44.983
1997	45.119
1998	45.171
1999	45.167
2000	45.149
2001	45.242
2002	45.203
2003	45.055
2004	44.796
2005	44.412
2006	44.316
2007	44.177
2008	44.047
2009	43.991
2010	44.053
2011	44.175
2012	44.243
2013	44.229
2014	44.097
2015	43.824
2016	43.582
2017	43.51
2018	43.438
2019	43.367
2020	43.295
2021	43.224
2022	43.152
2023	43.08
2024	43.009
2025	42.937
2026	42.866
2027	42.794
2028	42.722
2029	42.651
2030	42.579