Year years 1960 57.902 1961 58.842 1962 59.769 1963 60.646 1964 61.513 1965 62.501 1966 62.847 1967 63.231 1968 63.69 1969 64.127 1970 64.594 1971 65.077 1972 65.601 1973 66.149 1974 66.775 1975 67.311 1976 67.874 1977 68.805 1978 69.291 1979 69.763 1980 70.323 1981 71.003 1982 71.383 1983 71.741 1984 72.14 1985 72.447 1986 72.706 1987 72.924 1988 73.17 1989 73.383 1990 73.525 1991 73.671 1992 73.875 1993 74.092 1994 74.442 1995 74.692 1996 74.65 1997 74.64 1998 74.542 1999 74.664 2000 75.11 2001 75.66 2002 75.857 2003 76.194 2004 76.276 2005 76.437 2006 76.432 2007 76.474 2008 76.576 2009 76.79 2010 77.124 2011 77.485 2012 77.598 2013 77.618 2014 77.677 2015 77.728 2016 77.938 2017 78.139 2018 78.267 2019 78.306 2020 78.472 2021 77.362 2022 78.799