Year	Percent
1991	6.885
1992	6.421
1993	6.329
1994	6.692
1995	6.534
1996	6.227
1997	6.179
1998	6.13
1999	6.091
2000	5.373
2001	5.879
2002	6.188
2003	7.369
2004	7.08
2005	6.991
2006	6.087
2007	6.055
2008	6.061
2009	6.164
2010	6.447
2011	6.925
2012	7.071
2013	6.447
2014	6.308
2015	6.521
2016	6.751
2017	6.969
2018	6.929
2019	6.778
2020	6.639
2021	6.504
2022	6.322