Year	Percent
1990	61.933
1991	61.808
1992	61.934
1993	61.811
1994	61.658
1995	61.429
1996	61.25
1997	60.985
1998	60.764
1999	60.911
2000	60.813
2001	60.513
2002	60.295
2003	60.042
2004	59.904
2005	59.752
2006	59.743
2007	59.603
2008	59.877
2009	60.161
2010	60.323
2011	60.309
2012	60.398
2013	60.531
2014	60.75
2015	60.999
2016	61.451
2017	61.632
2018	61.762
2019	61.829
2020	61.827
2021	61.756
2022	61.625
2023	61.438
2024	61.196
2025	60.905
2026	60.57
2027	60.198
2028	59.811
2029	59.441
2030	59.109