Year	Percent
1990	58.121
1991	58.673
1992	59.31
1993	60.046
1994	60.888
1995	60.432
1996	59.297
1997	58.32
1998	57.989
1999	57.695
2000	54.625
2001	57.579
2002	55.214
2003	56.739
2004	55.67
2005	55.167
2006	54.848
2007	54.586
2008	54.373
2009	54.199
2010	56.024
2011	56.426
2012	57.469
2013	56.955
2014	57.416
2015	58.875
2016	57.737
2017	57.866
2018	57.956
2019	57.989
2020	57.956
2021	57.842
2022	57.662
2023	57.426
2024	57.155
2025	56.868
2026	56.563
2027	56.253
2028	55.952
2029	55.683
2030	55.459