Year	Number
1971	416001
1976	369012
1977	377044
1978	397184
1979	424300
1980	438709
1981	443355
1982	437515
1983	420973
1984	405342
1985	400698
1987	395978
1988	399891
1989	391240
1990	385235
1991	377191
1992	373132
1993	472281
1994	495522
1995	543037
1996	558625
1997	571956
1998	687653
1999	654142
2000	651191
2001	635159
2002	658721
2003	659599
2004	519183
2005	534159
2006	540543
2007	537921
2008	531393
2009	514603
2010	496307
2011	472309
2012	493637
2013	592759
2014	604130
2015	646028
2016	670876
2017	729757