Year	Percent
1990	56.725
1991	56.667
1992	56.881
1993	57.461
1994	58.522
1995	58.477
1996	58.196
1997	58.396
1998	59.181
1999	60.209
2000	60.511
2001	60.776
2002	61.433
2003	61.686
2004	61.31
2005	61.637
2006	62.024
2007	62.136
2008	62.04
2009	62.113
2010	62.535
2011	61.255
2012	61.448
2013	61.607
2014	62.166
2015	62.673
2016	63.093
2017	63.138
2018	63.207
2019	63.286
2020	63.367
2021	63.419
2022	63.471
2023	63.532
2024	63.61
2025	63.71
2026	63.798
2027	63.905
2028	64.028
2029	64.162
2030	64.309