Year	Percent
1990	56.593
1991	56.803
1992	57.756
1993	58.874
1994	59.91
1995	60.608
1996	60.787
1997	60.797
1998	60.669
1999	60.633
2000	61.997
2001	63.268
2002	64.457
2003	65.548
2004	66.531
2005	67.417
2006	68.246
2007	69.038
2008	68.358
2009	67.656
2010	66.919
2011	66.148
2012	66.438
2013	66.661
2014	67.4
2015	67.907
2016	68.476
2017	68.616
2018	68.737
2019	68.852
2020	68.967
2021	69.081
2022	69.182
2023	69.27
2024	69.344
2025	69.406
2026	69.456
2027	69.482
2028	69.509
2029	69.573
2030	69.701