Year	Total
1971	8128
1972	8341
1973	8560
1974	8786
1975	9019
1976	9262
1977	9514
1978	9776
1979	10050
1980	10330
1981	10620
1982	10920
1983	11240
1984	11560
1985	11880
1986	12240
1987	12630
1988	13060
1989	13520
1990	14050
1991	14540
1992	15040
1993	14650
1994	15090
1995	15500
1996	15890
1997	16260
1998	16770
1999	17170
2000	17570
2001	18010
2002	18440
2003	18900
2004	19370
2005	19850
2006	20360
2007	28760
2008	29580
2009	30370