Year	Percent
1991	5.872
1992	5.747
1993	7.698
1994	7.707
1995	7.6
1996	7.104
1997	7.174
1998	7.421
1999	7.597
2000	7.61
2001	7.728
2002	7.652
2003	7.586
2004	7.583
2005	7.501
2006	7.221
2007	6.544
2008	6.583
2009	7.06
2010	7.151
2011	6.841
2012	6.89
2013	6.864
2014	6.972
2015	6.921
2016	7.024
2017	7.051
2018	7.033
2019	7.028
2020	7.005
2021	7.015
2022	7.048
