Year	Total
1971	6453
1972	7006
1973	8640
1974	11170
1975	11940
1976	11850
1977	11840
1978	11170
1979	10910
1980	9441
1981	8346
1982	8591
1983	8606
1984	8681
1985	9433
1986	9126
1987	8645
1988	8836
1989	11160
1990	14630
1991	15930
1992	15860
1993	16830
1994	18490
1995	19770
1996	19910
1997	20140
1998	19160
1999	17230
2000	15140
2001	14430
2002	14120
2003	15120
2004	15110
2005	14940
2006	13540
2007	13790
2008	13510
2009	13590