Year	Percent
1991	7.261
1992	7.121
1993	7.497
1994	7.628
1995	7.908
1996	8.421
1997	8.931
1998	9.414
1999	9.862
2000	10.997
2001	11.583
2002	12.092
2003	12.756
2004	13.51
2005	14.399
2006	15.131
2007	15.674
2008	16.703
2009	17.961
2010	19.727
2011	20.669
2012	23.256
2013	25.071
2014	26.446
2015	27.716
2016	29.063
2017	29.731
2018	31.286
2019	32.744
2020	33.823
2021	34.861
2022	35.957