Year years 1960 49.064 1961 49.564 1962 50.076 1963 50.588 1964 50.926 1965 51.472 1966 51.991 1967 52.52 1968 53.075 1969 53.606 1970 54.18 1971 54.736 1972 55.239 1973 55.854 1974 56.355 1975 56.88 1976 57.381 1977 57.907 1978 58.446 1979 58.85 1980 59.495 1981 60.031 1982 60.507 1983 61.04 1984 61.515 1985 61.946 1986 62.642 1987 62.338 1988 63.603 1989 63.679 1990 64.063 1991 64.86 1992 64.981 1993 65.219 1994 65.418 1995 65.6 1996 66.535 1997 66.61 1998 66.653 1999 66.275 2000 66.865 2001 66.962 2002 67.159 2003 67.214 2004 67.257 2005 67.343 2006 67.427 2007 67.505 2008 67.566 2009 67.623 2010 67.599 2011 67.508 2012 67.472 2013 67.49 2014 67.499 2015 67.551 2016 67.652 2017 67.645 2018 67.75 2019 67.801 2020 68.547 2021 68.397 2022 68.316