Year	Percent
1990	56.016
1991	56.493
1992	57.803
1993	59.112
1994	60.392
1995	61.63
1996	62.699
1997	63.738
1998	64.762
1999	65.787
2000	66.815
2001	67.734
2002	68.392
2003	69.068
2004	69.763
2005	70.485
2006	71.176
2007	71.87
2008	72.568
2009	73.271
2010	73.987
2011	74.671
2012	75.354
2013	76.029
2014	76.691
2015	76.567
2016	76.34
2017	76.557
2018	76.772
2019	76.992
2020	77.218
2021	77.453
2022	77.692
2023	77.937
2024	78.186
2025	78.44
2026	78.7
2027	78.967
2028	79.237
2029	79.507
2030	79.776