Year	Number
1996	1.37
1997	3.69
1998	1.15
1999	6.99
2000	3.82
2001	3.17
2002	5.48
2003	6.53
2004	9.81
2005	13.48
2006	5.68
2007	2.61
2008	4.15
2009	5.89
2010	7.08
2011	7.94
2012	6.51
2013	7.85
2014	8.33
2015	10.63
2016	13.13
2017	10.47
2018	6.45
2019	9.9
2020	12.43