Year	Number
1977	17215
1979	11503
1980	9011
1981	14183
1982	12779
1983	26924
1984	29537
1985	30847
1986	24582
1987	19804
1988	15542
1991	17643
1992	22528
1993	9731
1994	11815
1995	11386
1996	9635
1999	3606
2000	3667
2001	3573
2002	4476
2003	7969
2004	14712
2005	15849
2006	14132
2007	10909
2008	8681
2009	8765
2010	9794
2011	9435
2012	7948
2013	7868
2014	7780
2015	6121