Year	Percent
1991	3.012
1992	3.16
1993	3.183
1994	3.226
1995	3.173
1996	3.088
1997	2.944
1998	2.956
1999	2.351
2000	2.266
2001	1.693
2002	2.303
2003	2.218
2004	2.712
2005	2.468
2006	2.48
2007	2.289
2008	1.97
2009	1.894
2010	1.73
2011	1.642
2012	1.569
2013	1.798
2014	1.545
2015	1.564
2016	1.676
2017	1.698
2018	1.678
2019	1.656
2020	1.633
2021	1.609
2022	1.586