Year	Percent
1991	48.964
1992	49.036
1993	48.987
1994	48.768
1995	48.369
1996	48.441
1997	48.278
1998	48.18
1999	47.692
2000	47.576
2001	47.17
2002	46.82
2003	46.368
2004	45.871
2005	45.364
2006	45.074
2007	44.71
2008	44.354
2009	44.015
2010	43.698
2011	43.562
2012	43.566
2013	43.349
2014	43.2
2015	42.935
2016	42.758
2017	42.487
2018	42.21
2019	41.931
2020	41.656
2021	41.387
2022	41.12