Year	Percent
1991	14.604
1992	14.316
1993	14.268
1994	14.185
1995	14.058
1996	13.915
1997	13.987
1998	13.907
1999	13.903
2000	14.009
2001	14.046
2002	14.11
2003	14.229
2004	14.434
2005	14.297
2006	14.127
2007	13.865
2008	13.694
2009	13.515
2010	13.467
2011	13.477
2012	13.641
2013	13.793
2014	13.899
2015	13.949
2016	13.977
2017	13.993
2018	13.99
2019	13.987
2020	14
2021	14.041
2022	14.116