Year	Percent
1990	38.83
1991	38.772
1992	38.724
1993	38.693
1994	38.695
1995	38.748
1996	38.977
1997	39.263
1998	39.612
1999	39.98
2000	40.298
2001	40.54
2002	40.761
2003	40.996
2004	41.179
2005	41.371
2006	41.623
2007	41.815
2008	42.035
2009	42.182
2010	42.343
2011	42.563
2012	42.743
2013	42.912
2014	43.067
2015	43.179
2016	43.292
2017	43.227
2018	43.126
2019	43.035
2020	42.971
2021	42.976
2022	43.008
2023	43.06
2024	43.123
2025	43.194
2026	43.31
2027	43.438
2028	43.575
2029	43.714
2030	43.855