Year	%
1997	2.79
1998	2.01
1999	2.49
2000	4.73
2001	4.43
2002	4.09
2003	3.9
2004	3.77
2005	4.83
2006	5.44
2007	5.88
2008	7.9
2009	9.55
2010	7.85
2011	7.09
2012	6.72
2013	6.79
2015	7.54
2016	8.15
2017	9.55
2018	8.16
2019	8.68
2020	8.79
2021	8.86