Year	Percent
1990	10.495
1991	11.425
1992	11.842
1993	11.798
1994	11.59
1995	11.087
1996	10.889
1997	10.347
1998	10.149
1999	11.094
2000	10.494
2001	10.132
2002	9.664
2003	9.379
2004	8.86
2005	8.553
2006	8.291
2007	8
2008	7.627
2009	7.27
2010	6.03
2011	3.96
2012	4.04
2013	5.29
2014	5.95
2015	4.99
2016	6.82
2017	6.463
2018	6.106
2019	5.749
2020	5.392
2021	5.035
2022	4.678
2023	4.321
2024	3.964
2025	3.607
2026	3.25
2027	2.893
2028	2.536
2029	2.179
2030	1.822