Year	Percent
1990	15.067
1991	15.143
1992	15.139
1993	15.416
1994	15.637
1995	15.809
1996	16.035
1997	16.348
1998	16.762
1999	17.267
2000	16.965
2001	16.691
2002	16.718
2003	17.309
2004	17.935
2005	18.593
2006	19.202
2007	18.72
2008	18.405
2009	17.994
2010	19.147
2011	20.54
2012	21.305
2013	21.277
2014	21.697
2015	23.119
2016	23.269
2017	23.358
2018	23.457
2019	23.546
2020	23.609
2021	23.496
2022	23.334
2023	23.144
2024	22.953
2025	22.776
2026	22.578
2027	22.398
2028	22.232
2029	22.073
2030	21.918