Year	Number of
1980	36716
1981	39992
1982	26457
1983	28634
1984	27589
1985	30960
1986	31029
1987	30531
1988	27884
1989	26669
1990	24468
1991	25166
1992	25455
1995	22981
1996	20212
1997	25685
1998	25501
1999	22088
2000	18038
2001	17263
2002	18043
2003	17923
2004	17543
2005	19744
2006	19629
2007	18878
2008	17603
2009	16771
2010	15879
2011	15054
2012	14139
2013	13170
2014	13108
2015	12550
2016	12186
2017	11821
2018	11576
2019	11247
2020	8830