Year	Percent
1991	32.137
1992	33.141
1993	35.037
1994	46.56
1995	49.194
1996	64.345
1997	50.092
1998	47.793
1999	45.325
2000	41.685
2001	41.165
2002	41.97
2003	41.092
2004	42.31
2005	41.516
2006	41.996
2007	41.237
2008	41.099
2009	29.713
2010	29.468
2011	28.957
2012	30.78
2013	30.101
2014	23.518
2015	25.728
2016	25.416
2017	25.181
2018	25.205
2019	25.229
2020	25.232
2021	25.256
2022	25.303