Year	Percent
1990	27.953
1991	28.087
1992	28.172
1993	28.2
1994	27.941
1995	27.684
1996	27.428
1997	27.174
1998	26.921
1999	26.669
2000	26.42
2001	26.171
2002	25.924
2003	25.679
2004	25.435
2005	25.193
2006	24.952
2007	24.713
2008	24.475
2009	24.239
2010	24.004
2011	23.771
2012	23.54
2013	23.509
2014	23.44
2015	23.38
2016	23.332
2017	23.163
2018	22.994
2019	22.824
2020	22.655
2021	22.486
2022	22.317
2023	22.147
2024	21.978
2025	21.809
2026	21.639
2027	21.47
2028	21.301
2029	21.132
2030	20.962