Year	Percent
1990	14.566
1991	14.626
1992	14.689
1993	14.713
1994	14.736
1995	14.833
1996	14.665
1997	14.504
1998	14.389
1999	14.316
2000	14.26
2001	14.487
2002	14.777
2003	15.078
2004	15.357
2005	15.61
2006	15.275
2007	14.948
2008	14.692
2009	14.576
2010	14.636
2011	15.173
2012	15.889
2013	16.736
2014	17.641
2015	18.552
2016	19.294
2017	19.359
2018	19.423
2019	19.486
2020	19.549
2021	19.613
2022	19.676
2023	19.739
2024	19.8
2025	19.861
2026	19.923
2027	19.983
2028	20.043
2029	20.104
2030	20.164