Year	Percent
1991	6.054
1992	7.117
1993	6.785
1994	5.997
1995	5.631
1996	5.741
1997	5.602
1998	5.633
1999	4.909
2000	3.984
2001	5.872
2002	3.48
2003	4.197
2004	4.028
2005	4.376
2006	3.919
2007	3.695
2008	3.701
2009	3.398
2010	3.74
2011	3.932
2012	3.944
2013	3.837
2014	3.956
2015	4.012
2016	4.038
2017	4.043
2018	4.053
2019	4.047
2020	4.053
2021	4.044
2022	4.041