| Year | Value | | 2023 | 4,141 | | 2022 | 4,109 | | 2021 | 4,039 | | 2020 | 3,924 | | 2019 | 3,778 | | 2018 | 3,617 | | 2017 | 3,439 | | 2016 | 3,258 | | 2015 | 3,068 | | 2014 | 2,874 | | 2013 | 2,725 | | 2012 | 2,674 | | 2011 | 2,730 | | 2010 | 2,851 | | 2009 | 2,959 | | 2008 | 2,973 | | 2007 | 2,838 | | 2006 | 2,586 | | 2005 | 2,301 | | 2004 | 2,066 | | 2003 | 1,939 | | 2002 | 1,942 | | 2001 | 2,029 | | 2000 | 2,120 | | 1999 | 2,170 | | 1998 | 2,180 | | 1997 | 2,174 | | 1996 | 2,165 | | 1995 | 2,148 | | 1994 | 2,116 | | 1993 | 2,073 | | 1992 | 2,016 | | 1991 | 1,945 | | 1990 | 1,873 | | 1989 | 1,811 | | 1988 | 1,750 | | 1987 | 1,689 | | 1986 | 1,633 | | 1985 | 1,577 | | 1984 | 1,529 | | 1983 | 1,493 | | 1982 | 1,465 | | 1981 | 1,442 | | 1980 | 1,425 | | 1979 | 1,398 | | 1978 | 1,352 | | 1977 | 1,294 | | 1976 | 1,226 | | 1975 | 1,155 |
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