Year	Percent
1990	55.662
1991	56.298
1992	56.868
1993	57.457
1994	58.165
1995	58.781
1996	59.396
1997	60.473
1998	63.975
1999	64.398
2000	64.821
2001	65.241
2002	65.66
2003	66.557
2004	67.222
2005	67.885
2006	69.115
2007	67.292
2008	65.411
2009	63.476
2010	62.294
2011	62.063
2012	63.69
2013	62.336
2014	61.748
2015	65.258
2016	69.047
2017	68.639
2018	68.232
2019	67.826
2020	67.422
2021	67.019
2022	66.617
2023	66.216
2024	65.816
2025	65.419
2026	65.024
2027	64.631
2028	64.239
2029	63.847
2030	63.454