Year	Total
1971	10670
1972	10080
1973	10830
1974	11460
1975	9960
1976	10330
1977	11990
1978	11710
1979	12090
1980	11990
1981	12950
1982	10610
1983	9913
1984	11130
1985	11090
1986	12610
1987	12890
1988	13160
1989	13360
1990	13440
1991	12980
1992	13480
1993	13860
1994	13590
1995	13650
1996	13920
1997	14290
1998	14730
1999	14530
2000	14860
2001	14870
2002	15270
2003	15630
2004	15830
2005	16130
2006	16500
2007	17020
2008	17490
2009	17550