Year	Number
1991	16651
1992	15867
1993	13483
1994	12661
1995	12393
1996	16661
1997	12821
1998	14226
1999	16449
2000	16157
2001	12625
2002	11309
2003	10872
2004	10463
2005	10484
2006	9456
2007	9552
2008	10040
2009	10848
2010	10813
2011	11985
2012	14608
2013	3002
2014	3659
2015	4834
2016	18933