Year	Number
1971	42557
1972	38011
1973	37548
1974	33966
1975	30472
1976	29294
1977	27175
1978	28536
1979	27386
1980	13892
1981	12674
1982	12880
1983	12398
1984	13530
1985	15235
1995	20531
1996	19025
2001	10075
2002	8930
2003	3588
2004	5472
2005	2614
2006	847
2007	2452
2014	1972
2015	1536
2016	3631
2017	5936
2018	16313