Year years 1960 42.371 1961 42.783 1962 42.986 1963 43.075 1964 43.09 1965 43.119 1966 43.157 1967 43.156 1968 43.162 1969 43.176 1970 43.238 1971 43.233 1972 43.357 1973 43.429 1974 43.494 1975 43.785 1976 43.878 1977 43.989 1978 44.084 1979 44.044 1980 44.153 1981 41.961 1982 42.169 1983 42.275 1984 42.21 1985 42.535 1986 44.833 1987 45.104 1988 45.678 1989 45.951 1990 46.264 1991 46.472 1992 46.721 1993 47.013 1994 47.134 1995 47.579 1996 48.142 1997 48.999 1998 49.607 1999 50.407 2000 51.11 2001 51.602 2002 52.181 2003 52.305 2004 52.636 2005 52.89 2006 53.273 2007 53.993 2008 54.692 2009 55.282 2010 55.837 2011 56.584 2012 57.521 2013 58.523 2014 59.439 2015 60.44 2016 61.475 2017 62.221 2018 63.234 2019 63.92 2020 64.16 2021 62.432 2022 62.688