Year	Percent
1991	46.139
1992	43.774
1993	42.183
1994	38.378
1995	38.649
1996	40.457
1997	39.856
1998	37.585
1999	33.313
2000	28.883
2001	28.9
2002	28.824
2003	29.241
2004	28.206
2005	28.288
2006	29.104
2007	30.826
2008	30.716
2009	26.74
2010	23.721
2011	24.819
2012	24.056
2013	24.416
2014	26.75
2015	28.379
2016	32.166
2017	32.203
2018	32.164
2019	31.527
2020	30.73
2021	29.918
2022	29.11