Year	Percent
1991	4.561
1992	4.364
1993	4.31
1994	3.39
1995	3.382
1996	3.41
1997	3.285
1998	3.394
1999	3.316
2000	3.168
2001	3.429
2002	3.323
2003	3.149
2004	3.155
2005	3.364
2006	4.557
2007	4.776
2008	4.943
2009	5.128
2010	4.285
2011	4.339
2012	4.407
2013	4.124
2014	4.17
2015	3.562
2016	3.343
2017	3.44
2018	3.44
2019	3.441
2020	3.441
2021	3.441
2022	3.441