Year	Percent
1991	11.544
1992	11.866
1993	12.781
1994	13.234
1995	10.725
1996	11.487
1997	12.298
1998	12.89
1999	13.259
2000	13.488
2001	13.213
2002	13.412
2003	14.216
2004	15.517
2005	16.822
2006	18.876
2007	19.252
2008	19.659
2009	20.735
2010	21.595
2011	21.942
2012	21.891
2013	21.832
2014	22.493
2015	22.432
2016	23.083
2017	23.18
2018	23.289
2019	23.407
2020	23.512
2021	23.62
2022	23.723