Year	Percent
1991	51.227
1992	51.373
1993	50.559
1994	50.758
1995	47.117
1996	45.071
1997	44.465
1998	39.353
1999	35.655
2000	42.798
2001	35.262
2002	32.091
2003	43.508
2004	50.716
2005	49.166
2006	46.33
2007	52.139
2008	49.345
2009	49.766
2010	46.927
2011	47.173
2012	43.761
2013	48.065
2014	48.881
2015	48.292
2016	34.149
2017	34.015
2018	33.9
2019	33.784
2020	33.667
2021	33.549
2022	33.431