Year years 1960 60.302 1961 60.589 1962 60.964 1963 61.378 1964 61.84 1965 61.996 1966 62.338 1967 62.758 1968 63.173 1969 63.825 1970 63.969 1971 64.391 1972 64.727 1973 64.61 1974 65.066 1975 65.175 1976 65.701 1977 65.578 1978 65.815 1979 65.996 1980 66.169 1981 66.413 1982 66.609 1983 66.826 1984 67.046 1985 67.336 1986 67.701 1987 68.002 1988 68.173 1989 68.317 1990 68.308 1991 68.109 1992 68.036 1993 67.734 1994 67.621 1995 67.691 1996 67.764 1997 67.856 1998 68.103 1999 68.438 2000 68.76 2001 69.126 2002 69.601 2003 70.067 2004 70.548 2005 70.301 2006 70.585 2007 71.034 2008 71.445 2009 71.572 2010 71.813 2011 72.225 2012 72.47 2013 72.841 2014 73.13 2015 73.324 2016 73.505 2017 73.773 2018 73.815 2019 73.883 2020 72.789 2021 73.39 2022 74.293