Year	Number
1996	5.95
1997	7.33
1998	4.11
1999	3.93
2000	6.08
2001	9.58
2002	16.13
2003	5.89
2004	9.73
2005	10.04
2006	12.07
2007	10.16
2008	11.85
2009	13.78
2010	13.18
2011	16.78
2012	20.63
2013	23.85
2014	32.02
2015	31.32
2016	37.06
2017	43.47
2018	28.88
2019	33.81
2020	45.41