Year	Percent
1991	22.228
1992	17.856
1993	15.274
1994	29.12
1995	28.394
1996	43.723
1997	32.724
1998	33.308
1999	29.993
2000	35.867
2001	32.412
2002	32.684
2003	32.333
2004	32.592
2005	32.198
2006	27.255
2007	26.452
2008	25.789
2009	22.46
2010	22.177
2011	16.426
2012	18.187
2013	20.519
2014	20.108
2015	20.925
2016	20.899
2017	21.319
2018	21.273
2019	21.239
2020	21.156
2021	21.272
2022	21.276