Year	Number
1971	53853
1972	76463
1973	105689
1974	122009
1975	126204
1976	125203
1977	113700
1978	109436
1979	100841
1980	61795
1981	63421
1982	84432
1983	115466
1984	118514
1985	141250
1986	104188
1987	46770
1988	11728
1991	46808
1992	80061
1998	906
1999	2098
2000	2006
2002	7394
2003	4066
2004	17363
2005	42
2006	15060
2007	54739
2008	22855
2009	38385
2010	34621
2011	36078
2012	29448