Year	Percent
1990	44.224
1991	44.177
1992	44.132
1993	44.049
1994	43.941
1995	43.803
1996	43.716
1997	43.608
1998	43.491
1999	43.338
2000	43.195
2001	43.05
2002	42.935
2003	42.845
2004	42.77
2005	42.686
2006	42.72
2007	42.781
2008	42.829
2009	42.656
2010	42.602
2011	42.585
2012	42.746
2013	42.699
2014	42.562
2015	42.446
2016	42.317
2017	42.149
2018	41.976
2019	41.803
2020	41.635
2021	41.474
2022	41.323
2023	41.177
2024	41.03
2025	40.878
2026	40.728
2027	40.577
2028	40.43
2029	40.289
2030	40.157