Year	Percent
1990	15.268
1991	15.333
1992	15.466
1993	15.55
1994	15.616
1995	15.702
1996	15.737
1997	15.809
1998	15.889
1999	15.911
2000	15.931
2001	15.871
2002	15.903
2003	15.866
2004	15.838
2005	15.781
2006	15.798
2007	15.828
2008	15.685
2009	15.402
2010	15.247
2011	15.14
2012	14.96
2013	17.6
2014	19.64
2015	16.36
2016	17.57
2017	17.625
2018	17.681
2019	17.736
2020	17.791
2021	17.847
2022	17.902
2023	17.957
2024	18.013
2025	18.068
2026	18.123
2027	18.179
2028	18.234
2029	18.289
2030	18.345