Year per 1000 people 1960 1 1961 1 1962 1 1963 1 1964 1 1965 1 1966 1 1967 1 1968 1 1969 1.1 1970 1.1 1971 1.1 1972 1.1 1973 1.1 1974 1.1 1975 1.1 1976 1.1 1977 1.2 1978 1.2 1979 1.2 1980 1.3 1981 1.3 1982 1.4 1984 1.4 1985 1.5 1986 1.5 1988 1.6 1990 1.733 1992 1.784 1994 1.858 1996 1.93 1998 1.985 2000 2.035 2002 2.081 2004 2.133 2006 2.186 2008 2.252 2010 2.227 2012 2.297 2014 2.367