Year	Number
1973	19594
1974	21246
1975	27312
1976	29714
1977	30572
1978	21847
1979	26811
1980	28662
1981	32028
1982	34619
1983	36219
1984	36327
1991	64513
1993	71467
2000	84869
2001	83651
2002	89586
2003	87302
2004	85858
2005	93803
2006	93727
2007	92965
2008	95296
2009	97491
2010	98089
2011	96447
2012	89901
2013	81749
2014	77685
2015	78418
2016	79425
2017	80914
2018	82664