Year	Percent
1991	1.472
1992	1.296
1993	2.057
1994	2.786
1995	3.233
1996	3.429
1997	4.883
1998	4.82
1999	9.073
2000	8.876
2001	7.641
2002	7.528
2003	7.504
2004	7.787
2005	7.973
2006	7.869
2007	7.85
2008	7.787
2009	8.047
2010	7.6
2011	7.869
2012	7.736
2013	8.107
2014	8.123
2015	8.115
2016	8.568
2017	8.789
2018	8.775
2019	8.768
2020	8.769
2021	8.77
2022	8.772