Year	Number
1996	4361.86
1997	4616.99
1998	4599.59
1999	4929.16
2000	5330.3
2001	5742.18
2002	6038.75
2003	6364.93
2004	6965.16
2005	7800
2006	8717.82
2007	9913.27
2008	10620.63
2009	10891.11
2010	12315.27
2011	13210.79
2012	13563.95
2013	13580.63
2014	14923.01
2015	16283.19
2016	16133.14
2017	16186.38
2018	15581.15
2019	16118.82
2020	14994