Year years 1960 45.481 1961 46.053 1962 46.698 1963 47.322 1964 48.332 1965 49.432 1966 50.273 1967 51.308 1968 52.31 1969 52.52 1970 52.91 1971 53.435 1972 53.582 1973 54.171 1974 54.533 1975 54.657 1976 55.256 1977 55.654 1978 55.761 1979 56.328 1980 56.787 1981 56.919 1982 57.416 1983 57.597 1984 57.993 1985 58.028 1986 58.477 1987 58.566 1988 58.625 1989 59.115 1990 59.176 1991 59.639 1992 59.823 1993 60.413 1994 60.811 1995 61.142 1996 62.029 1997 62.44 1998 63.123 1999 63.202 2000 63.338 2001 63.748 2002 63.918 2003 64.306 2004 64.368 2005 64.761 2006 64.781 2007 65.301 2008 57.787 2009 66.118 2010 66.215 2011 66.963 2012 67.182 2013 67.873 2014 68.168 2015 68.744 2016 68.838 2017 68.995 2018 69.676 2019 69.799 2020 69.959 2021 69.001 2022 70.478