Year	Percent
1990	47.289
1991	47.012
1992	46.759
1993	46.498
1994	46.219
1995	45.922
1996	45.749
1997	45.606
1998	45.491
1999	45.397
2000	45.317
2001	45.191
2002	44.674
2003	44.621
2004	45.934
2005	46.204
2006	46.15
2007	45.361
2008	45.904
2009	46.836
2010	46.193
2011	44.628
2012	44.557
2013	44.613
2014	46.506
2015	46.99
2016	45.556
2017	45.486
2018	45.42
2019	45.334
2020	45.215
2021	45.092
2022	44.956
2023	44.81
2024	44.663
2025	44.52
2026	44.393
2027	44.275
2028	44.166
2029	44.066
2030	43.976