Year	Percent
1991	7.692
1992	7.555
1993	7.883
1994	7.894
1995	7.631
1996	7.45
1997	7.604
1998	7.994
1999	8.123
2000	8.653
2001	10.923
2002	14.399
2003	18.306
2004	15.194
2005	12.489
2006	12.497
2007	12.374
2008	12.463
2009	12.74
2010	13.048
2011	15.131
2012	18.568
2013	23.795
2014	19.219
2015	15.904
2016	16.227
2017	16.32
2018	16.571
2019	16.684
2020	16.749
2021	16.833
2022	16.715