Year	Percent
1990	43.945
1991	44.629
1992	45.079
1993	45.014
1994	45.498
1995	44.975
1996	44.663
1997	44.956
1998	45.016
1999	44.995
2000	44.435
2001	43.942
2002	43.698
2003	43.386
2004	42.99
2005	42.576
2006	42.418
2007	41.78
2008	41.677
2009	42.205
2010	42.154
2011	41.541
2012	41.488
2013	41.68
2014	41.53
2015	41.33
2016	40.722
2017	40.647
2018	40.559
2019	40.434
2020	40.263
2021	40.132
2022	39.961
2023	39.769
2024	39.592
2025	39.455
2026	39.432
2027	39.445
2028	39.481
2029	39.522
2030	39.558