Year	Number
1996	3945.12
1997	4350.81
1998	4656.51
1999	4873.62
2000	5026.99
2001	5434.53
2002	5962.27
2003	6729.9
2004	7285.4
2005	8316.07
2006	9432.71
2007	9634.49
2008	10418.35
2009	10662.07
2010	11269.39
2011	11856.04
2012	12579.93
2013	13215.34
2014	14085.34
2015	14542.51
2016	15030.26
2017	16016.63
2018	16926.89
2019	18495.83
2020	20074.24