Year	Number
1980	1315
1981	1261
1982	1385
1983	1660
1984	1463
1989	1409
1990	2973
1991	3400
1992	3749
1993	4142
1994	4405
1995	3777
1997	5388
2012	7496
2013	7524
2014	7036
2015	11449
2016	10620
2017	9082