Year	Number
1996	21.65
1997	29.5
1998	33.26
1999	36.5
2000	23.61
2001	28.73
2002	29.88
2003	26.9
2004	32.45
2005	48.89
2006	42.17
2007	33.15
2008	41.38
2009	51.45
2010	42.93
2011	57.18
2012	50.02
2013	54.08
2014	60.1
2015	61.03
2016	59.25
2017	59.69
2018	61.04
2019	70.99
2020	60.98