Year	Percent
1990	51.875
1991	52
1992	52
1993	49.1
1994	51.9
1995	52.7
1996	53.05
1997	53.4
1998	53.3
1999	52.501
2000	51.7
2001	49.599
2002	47.5
2003	48.1
2004	48.7
2005	48.367
2006	48.033
2007	47.7
2008	46.252
2009	44.81
2010	38.8
2011	37.71
2012	38.298
2013	38.89
2014	37.74
2015	41.66
2016	40.856
2017	40.363
2018	39.87
2019	39.378
2020	38.885
2021	38.392
2022	37.899
2023	37.406
2024	36.913
2025	36.421
2026	35.928
2027	35.435
2028	34.942
2029	34.449
2030	33.957