Year	Number
1996	5.27
1997	7.88
1998	9.75
1999	4.68
2000	11.91
2001	9.11
2002	11.86
2003	11.81
2004	28.53
2005	15.56
2006	14.22
2007	15.91
2008	15.94
2009	11.79
2010	21.35
2011	17.55
2012	25.44
2013	31.74
2014	23.34
2015	29.02
2016	24.84
2017	24.79
2018	30.95
2019	27.91
2020	27.7