Year	Percent
1990	19.75
1991	22.17
1992	19.08
1993	19.84
1994	20.88
1995	21.65
1996	22.91
1997	23.47
1998	24.77
1999	23.79
2000	25.14
2001	26.25
2002	26.23
2003	25.7
2004	25.82
2005	24.63
2006	24.57
2007	24.18
2008	23.44
2009	22.26
2010	22.25
2011	22.17
2012	21.87
2013	20.52
2014	18.29
2015	17.68
2016	17.12
2017	16.956
2018	16.791
2019	16.627
2020	16.462
2021	16.298
2022	16.133
2023	15.969
2024	15.804
2025	15.64
2026	15.475
2027	15.311
2028	15.146
2029	14.982
2030	14.817