Year	Percent
1991	27.917
1992	29.32
1993	29.684
1994	27.216
1995	26.736
1996	24.178
1997	25.167
1998	23.601
1999	22.617
2000	21.878
2001	19.74
2002	18.988
2003	18.659
2004	16.789
2005	15.873
2006	14.556
2007	14.604
2008	14.815
2009	13.802
2010	13.23
2011	12.509
2012	12.041
2013	12.826
2014	13.161
2015	12.094
2016	12.513
2017	12.556
2018	12.26
2019	12.219
2020	12.075
2021	12.045
2022	12.004