Year	Percent
1991	16.277
1992	16.278
1993	17.286
1994	17.882
1995	17.915
1996	16.95
1997	16.296
1998	16.021
1999	15.716
2000	15.498
2001	12.953
2002	14.307
2003	12.83
2004	10.412
2005	8.622
2006	9.077
2007	10.549
2008	6.732
2009	6.149
2010	5.653
2011	5.462
2012	5.773
2013	6.135
2014	5.767
2015	6.67
2016	6.881
2017	6.855
2018	6.763
2019	6.634
2020	6.681
2021	6.634
2022	6.548
