Year years 1960 62.238 1961 62.673 1962 62.845 1963 63.584 1964 64.138 1965 64.405 1966 64.665 1967 64.655 1968 64.329 1969 64.41 1970 64.627 1971 64.717 1972 65.046 1973 65.506 1974 65.859 1975 66.109 1976 66.701 1977 67.025 1978 67.314 1979 67.784 1980 68.08 1981 68.593 1982 69.031 1983 69.035 1984 69.005 1985 69.355 1986 69.595 1987 70.354 1988 70.605 1989 71.064 1990 71.19 1991 70.941 1992 71.037 1993 70.753 1994 70.47 1995 70.224 1996 69.919 1997 69.627 1998 69.259 1999 69.132 2000 69.082 2001 68.782 2002 68.662 2003 68.429 2004 68.249 2005 68.454 2006 68.684 2007 69.189 2008 69.629 2009 70.114 2010 70.579 2011 71.176 2012 72.01 2013 72.234 2014 71.727 2015 70.798 2016 70.121 2017 69.916 2018 69.695 2019 69.668 2020 69.818 2021 68.469 2022 68.532