Year	Percent
1991	38.033
1992	50.847
1993	55.695
1994	57.028
1995	54.674
1996	50.141
1997	47.57
1998	46.351
1999	50.506
2000	47.3
2001	52.792
2002	52.4
2003	53.169
2004	51.744
2005	51.749
2006	53.479
2007	50.663
2008	48.874
2009	49.263
2010	47.357
2011	46.122
2012	44.389
2013	43.932
2014	42.587
2015	41.124
2016	40.733
2017	40.216
2018	39.077
2019	38.069
2020	36.904
2021	35.9
2022	34.971