Year	Percent
1991	14.056
1992	11.167
1993	10.185
1994	10.318
1995	10.741
1996	12.868
1997	14.45
1998	13.761
1999	14.914
2000	15.934
2001	16.408
2002	17.497
2003	17.653
2004	18.867
2005	20.355
2006	21.477
2007	27.243
2008	28.154
2009	32.519
2010	34.958
2011	34.252
2012	32.62
2013	35.871
2014	37.874
2015	38.32
2016	39.076
2017	39.257
2018	40.558
2019	41.666
2020	42.771
2021	44.009
2022	45.028