Year	Percent
1991	38.993
1992	52.619
1993	46.502
1994	47.019
1995	42.501
1996	12.796
1997	40.523
1998	35.336
1999	31.923
2000	39.401
2001	31.91
2002	27.553
2003	39.066
2004	46.759
2005	46.671
2006	43.334
2007	46.577
2008	45.593
2009	46.082
2010	43.884
2011	43.377
2012	37.574
2013	42.895
2014	43.284
2015	40.233
2016	38.437
2017	37.539
2018	37.171
2019	36.542
2020	35.805
2021	35.114
2022	34.579