Year	Percent
1990	43.049
1991	43.825
1992	45.11
1993	45.585
1994	46.69
1995	47.308
1996	48.34
1997	49.727
1998	50.575
1999	52.105
2000	53.22
2001	54.196
2002	54.885
2003	55.61
2004	56.095
2005	56.643
2006	57.19
2007	58.424
2008	59.239
2009	59.745
2010	58.249
2011	58.093
2012	58.625
2013	58.537
2014	57.814
2015	58.203
2016	58.02
2017	57.966
2018	57.914
2019	57.851
2020	57.766
2021	57.693
2022	57.61
2023	57.511
2024	57.394
2025	57.261
2026	57.154
2027	57.038
2028	56.914
2029	56.786
2030	56.653