Year	Percent
1991	14.577
1992	14.47
1993	11.984
1994	11.451
1995	10.693
1996	11.342
1997	10.599
1998	10.709
1999	9.642
2000	9.017
2001	8.443
2002	8.113
2003	7.643
2004	7.406
2005	6.722
2006	6.538
2007	6.49
2008	5.977
2009	6.314
2010	6.476
2011	6.801
2012	7.023
2013	6.618
2014	6.397
2015	6.797
2016	6.889
2017	6.824
2018	6.563
2019	6.417
2020	6.282
2021	6.147
2022	6.01