Year	Number
1973	470287
1978	499307
1980	497030
1981	487230
1982	471679
1983	440631
1984	421390
1985	407088
1986	406763
1987	389912
1988	390154
1993	480625
2000	686805
2001	590236
2002	602512
2003	564915
2004	551091
2005	516743
2006	307999
2007	220470
2008	85850
2009	109215
2010	39646