Year Number 1970 55900 1971 42000 1972 43000 1973 44500 1974 45000 1975 45000 1976 45000 1977 30000 1978 12000 1979 13000 1980 13000 1981 14500 1982 14700 1983 14000 1984 15700 1985 15800 1986 24500 1987 45000 1988 47500 1989 49600 1990 115400 1991 115400 1992 118500 1993 118500 1994 118500 1995 124500 1996 124500 1997 124500 1998 124100 1999 197200 2000 210847 2001 210847 2002 219598 2003 218652 2004 271706 2005 293442 2006 326730 2007 328326 2008 323401 2009 302596 2010 443778 2011 532707 2012 877949.881372257 2013 1476528 2014 1310124 2015 1181188 2016 1220201 2017 1196041 2018 1009414 2019 979307 2020 386950 2021 157293