Year	Percent
1991	40.894
1992	41.136
1993	39.268
1994	44.602
1995	38.986
1996	39.154
1997	38.709
1998	40.901
1999	39.002
2000	38.992
2001	39.511
2002	40.012
2003	45.44
2004	42.68
2005	43.18
2006	44.247
2007	44.653
2008	44.475
2009	43.252
2010	42.358
2011	41.938
2012	35.998
2013	38.432
2014	41.154
2015	41.815
2016	41.154
2017	42.262
2018	42.745
2019	43.424
2020	43.938
2021	44.336
2022	44.547