Year years 1960 43.04 1961 44.359 1962 45.861 1963 46.094 1964 47.161 1965 49.022 1966 51.56 1967 54.066 1968 54.916 1969 55.08 1970 56.516 1971 56.841 1972 57.349 1973 57.941 1974 58.042 1975 58.263 1976 58.576 1977 58.83 1978 59.325 1979 59.714 1980 59.739 1981 59.487 1982 59.558 1983 59.432 1984 59.487 1985 59.811 1986 57.527 1987 61.017 1988 61.334 1989 60.158 1990 61.471 1991 61.429 1992 61.284 1993 61.138 1994 61.069 1995 61.056 1996 61.097 1997 61.181 1998 61.187 1999 61.393 2000 61.655 2001 62.032 2002 62.6 2003 63.166 2004 63.731 2005 63.709 2006 64.398 2007 64.724 2008 65.079 2009 65.116 2010 65.249 2011 64.902 2012 65.746 2013 66.328 2014 66.845 2015 67.249 2016 67.492 2017 68.267 2018 68.355 2019 68.523 2020 67.785 2021 67.591 2022 68.794