Year per 1,000 people 1961 1.1 1962 1.2 1963 1.3 1964 1.3 1965 1.3 1966 1.3 1967 1.3 1968 1.3 1969 1.4 1970 1.4 1971 1.5 1972 1.6 1973 1.6 1974 1.6 1975 1.7 1976 1.7 1977 1.7 1978 1.8 1979 1.8 1980 1.8 1981 1.8 1982 1.9 1983 1.9 1984 1.9 1985 2 1986 2 1987 2.1 1988 2.1 1989 2.1 1990 2.1 1991 2.1 1992 2.1 1993 2.2 1994 2.1 1995 2.1 1996 2.1 1997 2.1 1998 1.8611 1999 2.1 2001 1.8871 2002 1.8969 2004 1.8971 2006 1.9086 2008 1.959 2010 2.0384 2012 2.3962 2013 2.4509 2014 2.4961 2015 2.5388 2016 2.3105 2017 2.6102 2018 2.428 2019 2.435 2020 2.433 2021 2.464