Year	Percent
1991	11.547
1992	11.353
1993	10.659
1994	10.597
1995	10.975
1996	10.833
1997	11.151
1998	11.171
1999	11.255
2000	11.167
2001	11.073
2002	11.266
2003	11.108
2004	11.086
2005	10.566
2006	10.266
2007	9.997
2008	9.531
2009	8.861
2010	8.517
2011	8.864
2012	8.81
2013	8.598
2014	8.412
2015	8.437
2016	8.683
2017	8.821
2018	8.684
2019	8.558
2020	8.518
2021	8.451
2022	8.4