Year	Percent
1995	11.92
1996	13.07
1997	14.94
1998	17.79
1999	18.88
2001	18.13
2002	18.26
2003	19.26
2004	18.21
2005	19.54
2006	17.94
2007	16.95
2008	15.69
2009	18.01
2011	15.61
2012	16.11
2013	15.95
2014	15.82
2015	19.89
2016	27.23
2017	29.2
2018	28.54
2019	27.84
2020	31.28