Year	Percent
1990	70.615
1991	70.529
1992	70.383
1993	68.396
1994	66.212
1995	65.636
1996	64.582
1997	63.201
1998	62.154
1999	66.235
2000	66.37
2001	65.118
2002	66.631
2003	66.621
2004	67.396
2005	67.98
2006	68.41
2007	68.978
2008	68.64
2009	68.622
2010	68.14
2011	68.478
2012	68.484
2013	68.227
2014	68.329
2015	68.365
2016	68.89
2017	68.976
2018	69.031
2019	69.081
2020	69.143
2021	69.22
2022	69.301
2023	69.382
2024	69.451
2025	69.501
2026	69.537
2027	69.562
2028	69.563
2029	69.525
2030	69.441