Year | Value | 2021 | 13,934 | 2020 | 9,812 | 2019 | 26,942 | 2018 | 25,740 | 2017 | 25,550 | 2016 | 24,549 | 2015 | 24,066 | 2014 | 23,580 | 2013 | 23,568 | 2012 | 21,880 | 2011 | 21,306 | 2010 | 19,882 | 2009 | 13,532 | 2008 | 12,306 | 2007 | 12,172 | 2006 | 11,274 | 2005 | 12,013 | 2004 | 11,807 | 2003 | 10,819 | 2002 | 10,808 | 2001 | 10,317 | 2000 | 10,435 | 1999 | 10,100 | 1998 | 10,100 | 1997 | 10,300 | 1996 | 9,700 | 1995 | 10,900 | 1994 | 9,900 | 1993 | 9,400 | 1992 | 10,000 | 1991 | 9,300 | 1990 | 10,300 | 1989 | 6,800 | 1988 | 11,300 | 1987 | 8,500 | 1986 | 8,200 | 1985 | 11,100 | 1984 | 13,000 | 1983 | 19,000 | 1982 | 15,200 | 1981 | 19,400 | 1980 | 22,500 | 1979 | 23,000 | 1978 | 22,800 | 1977 | 21,400 | 1976 | 23,500 | 1975 | 22,400 | 1974 | 23,800 | 1973 | 22,700 | 1972 | 21,400 | 1971 | 20,800 | 1970 | 20,200 |
|