Year	Number of
1974	5331
1975	5314
1976	5139
1977	4892
1978	4614
1979	4388
1980	4273
1981	4257
1982	4350
1983	4479
1984	4575
1985	4600
1986	4587
1987	4516
1988	4414
1989	4378
1990	4379
1991	4468
1992	4600
1993	4776
1994	4942
1995	5095
1996	5244
1997	5367
1998	5471
1999	5550
2000	5618
2001	5627
2002	5628
2003	5616
2004	5594
2005	5578
2006	5598
2007	5621
2008	5649
2009	5663
2010	5606
2011	5514
2012	5418
2013	5290
2014	5189
2015	5127