Year	Percent
1990	43.072
1991	43.07
1992	43.046
1993	43.023
1994	42.803
1995	42.557
1996	42.421
1997	41.775
1998	41.154
1999	40.56
2000	40.925
2001	41.312
2002	41.722
2003	42.468
2004	39.944
2005	42.039
2006	41.854
2007	42.87
2008	42.593
2009	42.459
2010	42.789
2011	43.438
2012	43.014
2013	44.378
2014	43.925
2015	43.538
2016	42.353
2017	42.462
2018	42.547
2019	42.614
2020	42.664
2021	42.692
2022	42.705
2023	42.7
2024	42.673
2025	42.622
2026	42.551
2027	42.465
2028	42.366
2029	42.263
2030	42.16