Year	Percent
1990	71.446
1991	71.391
1992	71.32
1993	71.262
1994	71.23
1995	71.223
1996	71.179
1997	71.128
1998	71.11
1999	71.097
2000	69.523
2001	67.848
2002	66.089
2003	64.268
2004	62.414
2005	60.548
2006	60.831
2007	61.159
2008	61.463
2009	61.749
2010	62.006
2011	62.25
2012	62.442
2013	62.612
2014	62.773
2015	62.938
2016	63.108
2017	63.035
2018	62.963
2019	62.887
2020	62.806
2021	62.719
2022	62.629
2023	62.547
2024	62.489
2025	62.461
2026	62.457
2027	62.481
2028	62.522
2029	62.566
2030	62.603