Year	Number
1971	45963
1972	43194
1973	41831
1977	56897
1978	58603
1981	53822
1982	50905
1983	44925
1986	53298
1987	80107
1988	89413
1989	92694
1990	70681
1991	86144
2005	142507
2006	142632
2007	114404
2008	85446
2009	85734
2010	79513
2011	90325
2012	85211