Year	Percent
1990	55.533
1991	55.971
1992	56.174
1993	56.587
1994	57.049
1995	57.528
1996	57.971
1997	58.487
1998	58.749
1999	58.983
2000	59.224
2001	59.884
2002	60.544
2003	61.203
2004	61.853
2005	62.481
2006	63.093
2007	61.389
2008	62.239
2009	62.365
2010	62.019
2011	61.652
2012	57.945
2013	58.822
2014	60.9
2015	54.51
2016	55.031
2017	55.147
2018	55.269
2019	55.396
2020	55.528
2021	55.672
2022	55.823
2023	55.978
2024	56.137
2025	56.295
2026	56.46
2027	56.627
2028	56.794
2029	56.955
2030	57.106