Year	Percent
1990	66.517
1991	66.199
1992	65.833
1993	65.42
1994	64.99
1995	64.64
1996	64.42
1997	64.596
1998	65.981
1999	64.85
2000	63.935
2001	64.555
2002	64.731
2003	63.078
2004	65.552
2005	65.984
2006	65.67
2007	66.375
2008	65.609
2009	65.563
2010	65.493
2011	63.947
2012	63.272
2013	63.24
2014	63.195
2015	62.851
2016	61.408
2017	60.899
2018	60.37
2019	59.817
2020	59.238
2021	58.626
2022	58
2023	57.372
2024	56.753
2025	56.153
2026	55.561
2027	54.994
2028	54.453
2029	53.936
2030	53.444