Year	Percent
1990	54.028
1991	50.221
1992	46.402
1993	46.399
1994	45.915
1995	44.134
1996	43.601
1997	43.691
1998	49.399
1999	46.22
2000	47.036
2001	46.936
2002	46.855
2003	46.783
2004	46.71
2005	46.63
2006	46.54
2007	46.444
2008	46.348
2009	46.264
2010	44.264
2011	44.686
2012	42.151
2013	46.091
2014	45.424
2015	45.594
2016	45.807
2017	45.789
2018	45.778
2019	45.773
2020	45.771
2021	45.759
2022	45.749
2023	45.74
2024	45.727
2025	45.706
2026	45.667
2027	45.623
2028	45.572
2029	45.511
2030	45.437