Year	Number
1970	3078.174
1971	3876.508
1972	4052.461
1973	4636.136
1974	5069.548
1975	5299.539
1976	5125.432
1977	5298.975
1978	5629.995
1979	6339.666
1980	6791.417
1981	6641.619
1982	7595.224
1983	7229.679
1984	8047.58
1985	7728.131
1986	8111.318
1987	7566.145
1988	7390.07
1989	7418.265
1990	7057.861
1991	8166.361
1992	8906.857
1993	8293.819
1994	7600.139
1995	6786.537
1996	5989.723
1997	4990.897
1998	3862.896
1999	3973.574
2000	5874.576
2001	6304.326
2002	6668.525
2003	6951.84
2004	7546.303
2005	7028.846
2006	6510.246
2007	7046.268
2008	7141.708
2009	5758.447
2010	5161.141
2011	4576.625
2012	3525.677
2013	3303.835