Year	Percent
1991	14.834
1992	15.096
1993	17.843
1994	18.352
1995	19.475
1996	19.351
1997	17.954
1998	16.502
1999	15.914
2000	15.207
2001	13.028
2002	14.914
2003	15.554
2004	13.509
2005	11.507
2006	11.46
2007	8.598
2008	5.903
2009	6.658
2010	6.488
2011	6.457
2012	6.345
2013	6.1
2014	6.744
2015	6.628
2016	5.542
2017	5.407
2018	5.15
2019	4.906
2020	4.754
2021	4.564
2022	4.403