Year years 1960 49.537 1961 50.183 1962 51.029 1963 51.525 1964 52.349 1965 53.335 1966 54.005 1967 55.307 1968 55.687 1969 56.119 1970 57.189 1971 57.989 1972 58.471 1973 59.078 1974 56.873 1975 57.434 1976 60.817 1977 61.334 1978 61.529 1979 61.91 1980 56.204 1981 52.484 1982 53.014 1983 53.236 1984 53.418 1985 53.922 1986 54.168 1987 54.587 1988 50.333 1989 53.293 1990 53.542 1991 58.436 1992 63.916 1993 63.974 1994 63.841 1995 63.66 1996 63.825 1997 63.254 1998 63.004 1999 63.295 2000 63.734 2001 64.041 2002 64.005 2003 61.525 2004 60.435 2005 60.137 2006 58.189 2007 58.215 2008 60.716 2009 63.266 2010 63.929 2011 64.876 2012 65.418 2013 65.694 2014 66.522 2015 67.515 2016 65.614 2017 67.513 2018 69.559 2019 69.559 2020 66.954 2021 68.2 2022 69.162