Year	Percent
1991	42.628
1992	43.235
1993	43.591
1994	43.59
1995	37.123
1996	39.837
1997	39.021
1998	38.832
1999	39.353
2000	39.994
2001	41.307
2002	42.184
2003	42.848
2004	42.317
2005	39.242
2006	42.86
2007	42.197
2008	41.926
2009	42.816
2010	42.113
2011	40.452
2012	38.1
2013	37.687
2014	37.763
2015	38.56
2016	39.191
2017	40.4
2018	41.636
2019	42.52
2020	42.903
2021	42.724
2022	42.442