Year Years 1960 3.913 1961 2.109 1962 1.849 1963 1.632 1964 3 1965 2.286 1966 3.203 1967 1.671 1968 1.674 1969 2.371 1970 2.96 1971 3.182 1972 3.412 1973 2.684 1974 2.736 1975 3.271 1976 3.315 1977 3.478 1978 2.946 1979 2.384 1980 1.699 1981 1.623 1982 1.224 1983 1.527 1984 1.803 1985 1.438 1986 1.158 1987 1.421 1988 1.509 1989 1.639 1990 2.884 1991 2.577 1992 2.891 1993 3.126 1994 2.008 1995 2.276 1996 2.34 1997 2.271 1998 2.412 1999 2.1 2000 1.828 2001 0.9975 2002 1.075 2003 0.7873 2004 2.113