Year Number 1970 84600 1971 86500 1972 83100 1973 85700 1974 87700 1975 89500 1976 89300 1977 90500 1978 93600 1979 95300 1980 97700 1981 95900 1982 109200 1983 111400 1984 111600 1985 115800 1986 122200 1987 122700 1988 132000 1989 145900 1990 152100 1991 150800 1992 157600 1993 168900 1994 174900 1995 191200 1996 218200 1997 220800 1998 250300 1999 276300 2000 289031 2001 284899 2002 242800 2003 189121 2004 144703 2005 134839 2006 125126 2007 139124 2008 158788 2009 168280 2010 224807 2011 244994 2012 257233.254295533 2013 266128 2014 263267 2015 250094 2016 229530 2017 216436 2018 219782 2019 225755 2020 81283.2 2021 96369.999