Year	Percent
1991	6.609
1992	5.347
1993	6.109
1994	5.152
1995	6.27
1996	5.723
1997	5.977
1998	5.609
1999	4.746
2000	5.491
2001	3.693
2002	4.086
2003	3.998
2004	3.986
2005	4.759
2006	4.34
2007	5.032
2008	4.128
2009	4.742
2010	4.703
2011	3.331
2012	2.852
2013	2.831
2014	3.91
2015	4.195
2016	4.191
2017	4.014
2018	3.863
2019	3.712
2020	3.579
2021	3.464
2022	3.351
