Year years 1960 47.933 1961 48.545 1962 49.225 1963 49.829 1964 50.851 1965 46.589 1966 50.174 1967 52.837 1968 53.45 1969 54.195 1970 54.873 1971 55.505 1972 56.125 1973 56.744 1974 57.299 1975 57.861 1976 58.485 1977 59.097 1978 59.507 1979 60.005 1980 60.609 1981 60.848 1982 61.42 1983 62.049 1984 62.325 1985 62.868 1986 63.338 1987 63.435 1988 63.803 1989 64.309 1990 64.792 1991 65.015 1992 65.627 1993 66.301 1994 66.368 1995 66.794 1996 66.867 1997 67.343 1998 67.458 1999 67.982 2000 67.975 2001 68.509 2002 68.696 2003 69.242 2004 67.113 2005 69.294 2006 69.812 2007 69.929 2008 69.939 2009 70.417 2010 70.434 2011 70.571 2012 70.78 2013 71.346 2014 71.466 2015 71.629 2016 71.751 2017 71.898 2018 72.403 2019 72.597 2020 70.982 2021 69.744 2022 70.437