Year	Percent
1990	70.739
1991	70.844
1992	68.564
1993	65.814
1994	61.348
1995	61.488
1996	62.521
1997	61.958
1998	61.297
1999	61.949
2000	62.744
2001	63.46
2002	62.855
2003	63.093
2004	62.993
2005	61.492
2006	60.908
2007	60.715
2008	61.34
2009	60.636
2010	61.327
2011	61.004
2012	61.88
2013	62.598
2014	62.947
2015	64.35
2016	65.525
2017	65.776
2018	66.038
2019	66.276
2020	66.464
2021	66.604
2022	66.685
2023	66.729
2024	66.773
2025	66.843
2026	66.934
2027	67.054
2028	67.18
2029	67.272
2030	67.305