Year	Percent
1990	63.136
1991	62.474
1992	61.109
1993	59.461
1994	58.623
1995	59.085
1996	59.26
1997	58.689
1998	58.142
1999	58.823
2000	58.346
2001	58.479
2002	58.591
2003	58.716
2004	58.4
2005	59.581
2006	59.216
2007	59.676
2008	59.787
2009	59.339
2010	58.898
2011	59.424
2012	59.679
2013	60.152
2014	60.341
2015	60.622
2016	60.666
2017	60.757
2018	60.846
2019	60.922
2020	60.979
2021	61
2022	61.008
2023	61.007
2024	61.001
2025	60.994
2026	61.012
2027	61.035
2028	61.056
2029	61.058
2030	61.033