Year	Percent
1990	32.962
1991	33.681
1992	34.193
1993	34.977
1994	35.83
1995	36.706
1996	37.409
1997	38.187
1998	38.979
1999	39.361
2000	39.9
2001	40.826
2002	41.758
2003	42.696
2004	43.64
2005	44.588
2006	45.54
2007	50.69
2008	43.62
2009	42.15
2010	41.443
2011	40.74
2012	38.51
2013	42.34
2014	44.03
2015	40.64
2016	41.276
2017	41.275
2018	41.275
2019	41.274
2020	41.273
2021	41.272
2022	41.272
2023	41.271
2024	41.27
2025	41.269
2026	41.269
2027	41.268
2028	41.267
2029	41.266
2030	41.266