Year	Percent
1990	34.554
1991	34.826
1992	35.064
1993	35.39
1994	35.751
1995	35.963
1996	35.795
1997	35.595
1998	35.328
1999	35.036
2000	34.72
2001	34.404
2002	34.06
2003	33.699
2004	33.406
2005	33.162
2006	33.149
2007	33.176
2008	33.136
2009	33.225
2010	33.314
2011	33.436
2012	33.548
2013	33.621
2014	33.69
2015	33.73
2016	33.641
2017	33.588
2018	33.534
2019	33.481
2020	33.428
2021	33.374
2022	33.321
2023	33.267
2024	33.214
2025	33.161
2026	33.107
2027	33.054
2028	33
2029	32.947
2030	32.894