Year	Percent
1990	32.846
1991	32.5
1992	33.586
1993	34.689
1994	32.498
1995	36.038
1996	35.984
1997	35.929
1998	35.707
1999	35.486
2000	35.882
2001	36.28
2002	36.68
2003	36.47
2004	38.51
2005	39.55
2006	39.56
2007	36.83
2008	40.39
2009	40.357
2010	40.325
2011	40.292
2012	40.26
2013	43.481
2014	42.822
2015	42.811
2016	42.8
2017	43.009
2018	43.217
2019	43.426
2020	43.635
2021	43.843
2022	44.052
2023	44.26
2024	44.469
2025	44.678
2026	44.886
2027	45.095
2028	45.304
2029	45.512
2030	45.721