Year	Percent
1990	43.81
1991	44.502
1992	42.747
1993	42.286
1994	42.487
1995	42.678
1996	43.297
1997	43.759
1998	44.556
1999	45.55
2000	46.158
2001	47.067
2002	48.024
2003	48.793
2004	50.684
2005	50.402
2006	50.661
2007	50.452
2008	51.396
2009	50.854
2010	50.876
2011	51.29
2012	53.224
2013	53.33
2014	54.127
2015	53.826
2016	54.897
2017	54.976
2018	55.037
2019	55.085
2020	55.126
2021	55.144
2022	55.15
2023	55.161
2024	55.198
2025	55.276
2026	55.373
2027	55.514
2028	55.691
2029	55.887
2030	56.093