Year	Number
1971	105295
1972	103130
1973	97071
1974	120017
1975	135021
1976	152106
1977	167457
1978	154577
1982	192719
1983	280649
1984	297298
1985	307718
1986	309736
1987	258062
1988	264398
1989	276438
1991	298759
1992	312273
1993	311839
1994	311531
1995	305380
1996	291886
1997	290877
1998	298103
1999	326990
2000	316939
2001	314654
2002	308105
2003	297711
2004	294098
2005	285460
2006	274922
2007	267516
2008	268430
2009	277991
2013	306282
2014	287096
2015	286477
2016	293043
2017	286476