Year	Number
1971	84343
1972	91401
1973	136000
1974	146971
1975	161309
1976	172134
1978	198737
1979	209987
1980	222235
1981	227418
1982	232400
1983	236000
1984	244700
1985	252100
1986	262626
1987	267805
1988	272700
1989	275300
1990	281300
1991	274700
1992	257100
1993	230700
1994	228170
1995	222214
1996	227811
1997	184100
1998	190246
1999	195645
2000	216597
2001	247711
2002	269033
2003	295874
2004	312634
2005	318765
2006	307249
2007	303243
2008	297883
2009	279454
2010	248100