Year	Number
1996	1.01
1997	3.25
1998	1.5
1999	3.58
2000	2.79
2001	4.51
2002	4.42
2003	4.54
2004	11.37
2005	9.04
2006	9.91
2007	4.32
2008	6.21
2009	9.25
2010	3.84
2011	7.06
2012	4.56
2013	5.18
2014	8.66
2015	9.36
2016	10.84
2017	14.91
2018	15.81
2019	14.12
2020	14.07