Year	Percent
1990	59.936
1991	59.875
1992	59.696
1993	59.571
1994	59.472
1995	59.284
1996	59.231
1997	59.1
1998	59.903
1999	60.7
2000	62.229
2001	63.733
2002	65.212
2003	66.661
2004	68.08
2005	67.374
2006	66.66
2007	65.938
2008	65.209
2009	64.473
2010	63.73
2011	62.98
2012	63.041
2013	63.061
2014	63.071
2015	63.043
2016	62.989
2017	62.91
2018	62.831
2019	62.752
2020	62.673
2021	62.594
2022	62.515
2023	62.436
2024	62.357
2025	62.278
2026	62.199
2027	62.12
2028	62.041
2029	61.962
2030	61.883