Year	Percent
1990	67.723
1991	67.991
1992	68.443
1993	68.725
1994	69.164
1995	69.445
1996	69.581
1997	69.816
1998	69.884
1999	69.878
2000	69.924
2001	69.959
2002	69.999
2003	70.008
2004	69.992
2005	69.934
2006	69.872
2007	69.798
2008	69.708
2009	69.625
2010	69.532
2011	69.421
2012	69.305
2013	69.187
2014	69.079
2015	69.01
2016	68.97
2017	68.945
2018	68.94
2019	68.959
2020	69.005
2021	69.074
2022	69.168
2023	69.275
2024	69.377
2025	69.463
2026	69.532
2027	69.581
2028	69.612
2029	69.63
2030	69.634