Year	Percent
1990	78.621
1991	79.48
1992	80.391
1993	79.87
1994	79.9
1995	77.452
1996	74.801
1997	71.95
1998	68.911
1999	65.7
2000	67.623
2001	69.488
2002	71.291
2003	73.029
2004	74.7
2005	76.3
2006	75.619
2007	74.843
2008	74.039
2009	73.291
2010	72.239
2011	71.197
2012	70.298
2013	69.24
2014	68.173
2015	67.126
2016	66.255
2017	66.254
2018	66.252
2019	66.251
2020	66.25
2021	66.248
2022	66.247
2023	66.246
2024	66.244
2025	66.243
2026	66.242
2027	66.241
2028	66.239
2029	66.238
2030	66.237