Year Number 1960 -17662 1961 -18224 1962 -18971 1963 -21220 1964 -31125 1965 -36419 1966 -47780 1967 -55265 1968 -54963 1969 -45586 1970 -31405 1971 -17235 1972 -7848 1973 -6736 1974 -8670 1975 -11596 1976 -14515 1977 -16444 1978 -16654 1979 -16058 1980 -15067 1981 -13892 1982 -9799 1983 684 1984 9108 1985 -31640 1986 -21071 1987 50702 1988 -3008 1989 -3026 1990 -476 1991 2116 1992 4411 1993 5975 1994 7434 1995 8763 1996 9810 1997 10417 1998 -13145 1999 -13857 2000 -11501 2001 -25657 2002 -35034 2003 -35960 2004 -32854 2005 -28157 2006 -23450 2007 -20334 2008 -23981 2009 -25908 2010 -26350 2011 -26662 2012 -26918 2013 -26976 2014 -27076 2015 -22904 2016 -22774 2017 -25452 2018 -25137 2019 -24737 2020 -12369 2021 -12369 2022 -5000 2023 -5000