Year	Percent
1991	17.132
1992	12.303
1993	9.456
1994	22.482
1995	21.664
1996	40.318
1997	26.935
1998	27.802
1999	23.835
2000	30.288
2001	26.58
2002	26.792
2003	25.888
2004	26.06
2005	25.142
2006	22.16
2007	21.478
2008	19.237
2009	14.904
2010	15.125
2011	11.252
2012	12.623
2013	14.591
2014	13.864
2015	15.485
2016	15.518
2017	15.93
2018	15.878
2019	15.837
2020	15.754
2021	15.844
2022	15.838