Year years 1960 67.745 1961 67.168 1962 67.415 1963 69.508 1964 69.398 1965 67.768 1966 69.863 1967 71.168 1968 71.185 1969 72.353 1970 73.058 1971 72.096 1972 73.057 1973 73.469 1974 73.741 1975 73.957 1976 73.938 1977 73.434 1978 73.126 1979 73.287 1980 72.998 1981 73.492 1982 74.539 1983 74.559 1984 74.305 1985 74.234 1986 74.408 1987 74.255 1988 74.606 1989 74.233 1990 74.465 1991 74.331 1992 74.804 1993 74.614 1994 74.662 1995 74.719 1996 75.135 1997 76.027 1998 75.743 1999 77.269 2000 76.773 2001 76.773 2002 77.085 2003 76.388 2004 76.478 2005 77.727 2006 78.105 2007 77.835 2008 78.141 2009 78.065 2010 77.989 2011 77.115 2012 77.052 2013 78.188 2014 80.514 2015 80.616 2016 79.584 2017 78.17 2018 78.129 2019 78.797 2020 77.883 2021 76.696 2022 77.141