Year	Percent
1990	42.214
1991	42.023
1992	43.045
1993	36.742
1994	33.917
1995	34.109
1996	36.914
1997	35.105
1998	35.541
1999	33.818
2000	33.488
2001	31.786
2002	31.528
2003	31.033
2004	30.543
2005	30.056
2006	29.872
2007	26.638
2008	27.535
2009	28.373
2010	29.99
2011	27.892
2012	26.888
2013	27.819
2014	31.139
2015	32.063
2016	34.241
2017	33.809
2018	33.378
2019	32.947
2020	32.516
2021	32.084
2022	31.653
2023	31.222
2024	30.79
2025	30.359
2026	29.928
2027	29.496
2028	29.065
2029	28.634
2030	28.203