Year years 1960 54.596 1961 54.938 1962 55.105 1963 55.432 1964 55.779 1965 56.31 1966 56.49 1967 56.75 1968 57.158 1969 57.512 1970 57.794 1971 58.151 1972 58.417 1973 58.621 1974 58.831 1975 59.067 1976 59.203 1977 58.985 1978 59.215 1979 59.293 1980 59.799 1981 60.089 1982 60.407 1983 60.673 1984 60.855 1985 61.144 1986 61.654 1987 61.889 1988 62.056 1989 62.198 1990 62.344 1991 62.132 1992 62.169 1993 61.929 1994 61.769 1995 61.639 1996 61.702 1997 61.722 1998 62.014 1999 62.373 2000 62.727 2001 63.086 2002 63.636 2003 64.043 2004 64.302 2005 64.695 2006 65.202 2007 65.559 2008 66.086 2009 66.18 2010 66.655 2011 67.067 2012 67.277 2013 67.174 2014 67.379 2015 67.657 2016 68.016 2017 68.257 2018 68.479 2019 68.782 2020 67.876 2021 68.334 2022 69.032