Year	Percent
1990	42.276
1991	42.31
1992	42.417
1993	42.502
1994	42.688
1995	42.852
1996	42.946
1997	43.041
1998	43.149
1999	43.251
2000	43.384
2001	43.49
2002	43.622
2003	43.753
2004	43.954
2005	44.166
2006	44.508
2007	44.94
2008	45.33
2009	45.668
2010	46.033
2011	46.507
2012	47.009
2013	47.533
2014	48.062
2015	48.565
2016	49.115
2017	49.546
2018	49.965
2019	50.367
2020	50.75
2021	51.11
2022	51.451
2023	51.76
2024	52.027
2025	52.25
2026	52.43
2027	52.572
2028	52.677
2029	52.758
2030	52.82