Year	Percent
1991	43.592
1992	45.4
1993	45.723
1994	40.555
1995	37.65
1996	41.347
1997	42.973
1998	39.895
1999	46.44
2000	46.797
2001	47.106
2002	48.042
2003	47.71
2004	48.209
2005	47.716
2006	46.045
2007	45.892
2008	44.01
2009	44.101
2010	43.769
2011	43.418
2012	41.835
2013	41.217
2014	40.559
2015	40.151
2016	40.977
2017	41.071
2018	40.694
2019	40.152
2020	39.723
2021	39.376
2022	39.092