Year	Number
1971	12645
1972	14272
1973	14666
1974	17377
1975	19896
1976	20709
1977	21119
1978	21317
1979	23144
1980	23882
1981	24620
1982	25648
1983	26521
1984	27670
1986	24589
1994	21042
1995	22795
1998	29944
1999	35484
2000	36352
2002	38172
2004	31302
2005	40001
2007	35115
2008	41314
2009	29575
2010	38002
2011	39365
2012	41643
2013	42078
2014	44329
2015	46223
2016	46763
2017	48770
2018	75571