Year	Percent
1991	22.79
1992	23.931
1993	23.006
1994	22.593
1995	22.996
1996	23.15
1997	23.927
1998	25.671
1999	26.95
2000	27.71
2001	29.177
2002	30.768
2003	31.057
2004	31.472
2005	29.061
2006	30.419
2007	30.784
2008	30.705
2009	31.198
2010	31.461
2011	31.515
2012	32.186
2013	31.53
2014	32.297
2015	32.016
2016	33.675
2017	34.716
2018	34.545
2019	34.564
2020	37.812
2021	37.179
2022	35.453