Year	Percent
1991	36.248
1992	33.415
1993	33.833
1994	33.608
1995	32.724
1996	32.979
1997	31.624
1998	32.223
1999	31.686
2000	32.438
2001	30.988
2002	33.263
2003	33.763
2004	33.041
2005	33.43
2006	33.586
2007	34.204
2008	34.738
2009	35.109
2010	36.212
2011	36.986
2012	39.08
2013	42.24
2014	42.906
2015	39.079
2016	39.387
2017	39.632
2018	40.554
2019	41.391
2020	42.495
2021	43.603
2022	44.717