Year	Percent
1991	23.836
1992	23.034
1993	23.539
1994	26.922
1995	27.293
1996	28.058
1997	25.971
1998	26.823
1999	27.515
2000	30.763
2001	29.383
2002	30.979
2003	29.977
2004	31.492
2005	31.607
2006	31.009
2007	31.887
2008	32.484
2009	31.321
2010	30.94
2011	30.263
2012	29.935
2013	30.283
2014	30.056
2015	29.923
2016	28.077
2017	25.87
2018	26.038
2019	26.091
2020	26.143
2021	26.149
2022	26.201