Year	Number
1981	502400
1982	515300
1983	533600
1984	537600
1985	558300
1986	576700
1987	600400
1988	616900
1990	570400
1991	543600
1992	550800
1993	544300
1994	529000
1999	354373
2000	353003
2001	346106
2002	333634
2003	326213
2004	319633
2005	319580
2006	311289
2007	297306
2008	282279
2009	272224
2010	241706
2011	257951
2012	256962
2013	271345
2014	243100
2015	193164
2016	186191
2017	178989
2018	177070