Year	Percent
1991	32.764
1992	31.586
1993	30.464
1994	31.943
1995	32.943
1996	31.246
1997	32.083
1998	31.535
1999	29.804
2000	31.141
2001	32.46
2002	32.461
2003	32.743
2004	32.496
2005	35.151
2006	38.097
2007	40.858
2008	42.526
2009	41.747
2010	42.607
2011	41.713
2012	41.886
2013	41.469
2014	41.895
2015	42.391
2016	42.651
2017	41.746
2018	42.127
2019	42.487
2020	42.735
2021	42.539
2022	42.525