Year	Percent
1991	14.285
1992	13.802
1993	13.634
1994	13.344
1995	13.744
1996	13.997
1997	14.4
1998	20.445
1999	20.611
2000	20.672
2001	20.929
2002	21.371
2003	21.372
2004	21.803
2005	22.171
2006	22.463
2007	22.886
2008	23.163
2009	24.264
2010	24.272
2011	21.614
2012	13.614
2013	16.567
2014	15.79
2015	14.915
2016	12.795
2017	12.398
2018	11.351
2019	11.041
2020	11.288
2021	11.898
2022	11.772