Year	Percent
1991	16.233
1992	14.439
1993	13.791
1994	13.428
1995	12.722
1996	12.729
1997	12.665
1998	13.211
1999	13.001
2000	13.34
2001	12.774
2002	14.135
2003	13.177
2004	15.216
2005	15.989
2006	15.809
2007	15.098
2008	15.988
2009	16.603
2010	14.769
2011	14.366
2012	14.089
2013	14.281
2014	14.229
2015	13.809
2016	13.573
2017	13.179
2018	13.252
2019	13.202
2020	13.19
2021	13.186
2022	13.149