Year	Total
1971	7341
1972	7626
1973	7813
1974	7865
1975	8134
1976	8529
1977	8833
1978	9003
1979	9206
1980	9515
1981	9642
1982	9757
1983	9987
1984	10440
1985	11100
1986	11210
1987	10930
1988	10630
1989	10920
1990	10650
1991	10480
1992	10810
1993	10400
1994	10950
1995	11000
1996	10910
1997	11170
1998	12160
1999	13670
2000	15410
2001	15840
2002	16460
2003	18360
2004	20550
2005	23120
2006	22950
2007	23850
2008	22990
2009	22360