Year	Percent
1991	21.24
1992	18.273
1993	12.02
1994	15.349
1995	12.589
1996	12.43
1997	12.444
1998	10.755
1999	11.376
2000	9.916
2001	9.039
2002	8.852
2003	8.992
2004	8.322
2005	8.725
2006	8.171
2007	7.804
2008	6.499
2009	5.37
2010	5.814
2011	6.368
2012	7.518
2013	6.507
2014	8.045
2015	7.523
2016	7.476
2017	7.731
2018	7.983
2019	7.771
2020	7.593
2021	7.479
2022	7.36