Year	Percent
1991	62.095
1992	60.573
1993	60.294
1994	62.838
1995	62.254
1996	64.256
1997	57.673
1998	54.794
1999	50.699
2000	48.476
2001	46.846
2002	49.73
2003	48.395
2004	45.749
2005	44.517
2006	41.165
2007	39.609
2008	39.08
2009	40.058
2010	39.196
2011	38.389
2012	37.168
2013	36.016
2014	34.019
2015	32.936
2016	32.508
2017	33.083
2018	32.099
2019	31.601
2020	30.992
2021	30.348
2022	29.655