Year Number 1975 7000 1976 10000 1977 13000 1978 20000 1979 25000 1980 27000 1981 33800 1982 34000 1983 38000 1984 40000 1985 60000 1986 65000 1987 8400 1988 8400 1989 8400 1990 9400 1991 9400 1992 9400 1993 9400 1994 38500 1995 158600 1996 206900 1997 188900 1998 247200 1999 261100 2000 315108 2001 56216 2002 57902 2003 60218 2004 75875 2005 81945 2006 93417 2007 92483 2008 91096 2009 85448 2014 1024693.84477856 2015 1313533 2016 1409704 2017 1485752 2018 1191383.08265957 2019 1221786.67512409 2020 292931 2021 277881.434