Year	Percent
1991	3.169
1992	3.081
1993	2.85
1994	2.847
1995	2.731
1996	2.603
1997	2.517
1998	2.378
1999	2.219
2000	2.171
2001	1.989
2002	1.975
2003	1.811
2004	1.853
2005	1.927
2006	1.934
2007	1.889
2008	1.381
2009	1.595
2010	1.746
2011	1.709
2012	1.622
2013	1.456
2014	1.728
2015	1.566
2016	1.559
2017	1.545
2018	1.523
2019	1.501
2020	1.475
2021	1.448
2022	1.422