Year	Percent
1990	44.454
1991	44.356
1992	44.74
1993	44.796
1994	45.29
1995	45.262
1996	45.678
1997	45.564
1998	45.582
1999	46.011
2000	46.022
2001	46.067
2002	46.506
2003	47.069
2004	47.693
2005	48.082
2006	48.712
2007	49.51
2008	49.701
2009	49.616
2010	49.86
2011	49.995
2012	50.304
2013	50.562
2014	50.666
2015	50.79
2016	50.651
2017	50.396
2018	50.152
2019	49.906
2020	49.648
2021	49.409
2022	49.17
2023	48.91
2024	48.602
2025	48.226
2026	47.827
2027	47.371
2028	46.868
2029	46.341
2030	45.805
