Year	Percent
1991	29.922
1992	29.982
1993	30.047
1994	30.059
1995	30.146
1996	30.201
1997	30.296
1998	30.403
1999	30.534
2000	30.771
2001	30.911
2002	31.083
2003	31.28
2004	31.494
2005	31.721
2006	31.918
2007	32.113
2008	32.317
2009	32.544
2010	32.781
2011	32.988
2012	33.213
2013	33.451
2014	33.682
2015	33.909
2016	34.101
2017	34.277
2018	34.451
2019	34.62
2020	34.783
2021	34.93
2022	35.073