Year	Percent
1990	14.755
1991	14.643
1992	14.521
1993	14.394
1994	14.259
1995	14.119
1996	14.017
1997	13.901
1998	13.75
1999	18.665
2000	24.83
2001	24.517
2002	24.206
2003	23.898
2004	23.593
2005	23.29
2006	22.99
2007	22.849
2008	22.709
2009	22.57
2010	21.81
2011	23.386
2012	25.04
2013	26.77
2014	26.697
2015	26.602
2016	26.544
2017	26.657
2018	26.77
2019	26.884
2020	26.997
2021	27.11
2022	27.223
2023	27.337
2024	27.45
2025	27.563
2026	27.676
2027	27.79
2028	27.903
2029	28.016
2030	28.129