Year	Percent
1990	26.706
1991	27.465
1992	28.077
1993	29.031
1994	27.825
1995	27.108
1996	26.955
1997	26.483
1998	25.328
1999	25.567
2000	24.849
2001	24.3
2002	27.2
2003	26.443
2004	25.7
2005	24.583
2006	23.5
2007	26.344
2008	29.4
2009	25.425
2010	21.821
2011	18.6
2012	18.7
2013	16.9
2014	17.247
2015	17.6
2016	17.347
2017	17.112
2018	16.877
2019	16.642
2020	16.407
2021	16.172
2022	15.937
2023	15.702
2024	15.467
2025	15.231
2026	14.996
2027	14.761
2028	14.526
2029	14.291
2030	14.056