Year	Percent
1990	18.744
1991	20.116
1992	20.757
1993	21.885
1994	23.512
1995	24.496
1996	24.2
1997	23.728
1998	23.756
1999	23.245
2000	21.945
2001	20.351
2002	19.28
2003	15.71
2004	12.98
2005	12.576
2006	12.184
2007	11.802
2008	11.43
2009	10.236
2010	9.154
2011	8.176
2012	7.294
2013	6.5
2014	6.58
2015	6.661
2016	6.67
2017	6.36
2018	6.049
2019	5.739
2020	5.428
2021	5.118
2022	4.808
2023	4.497
2024	4.187
2025	3.877
2026	3.566
2027	3.256
2028	2.945
2029	2.635
2030	2.325