Year	Percent
1991	11.842
1992	10.56
1993	9.102
1994	9.59
1995	9.579
1996	8.781
1997	8.752
1998	7.399
1999	7.323
2000	7.599
2001	8.307
2002	7.445
2003	8.965
2004	7.157
2005	5.226
2006	3.642
2007	7.199
2008	3.565
2009	3.545
2010	3.628
2011	3.652
2012	3.736
2013	3.93
2014	3.904
2015	3.86
2016	3.921
2017	3.876
2018	3.777
2019	3.897
2020	3.945
2021	3.96
2022	3.972