Year years 1960 42.237 1961 42.661 1962 43.098 1963 43.505 1964 43.973 1965 44.309 1966 44.677 1967 45.178 1968 45.61 1969 46.137 1970 46.711 1971 47.034 1972 47.59 1973 48.064 1974 48.404 1975 48.66 1976 48.735 1977 48.759 1978 48.745 1979 48.754 1980 48.695 1981 48.58 1982 48.47 1983 48.387 1984 48.361 1985 48.438 1986 48.609 1987 48.924 1988 49.298 1989 49.839 1990 50.387 1991 51.039 1992 51.712 1993 52.535 1994 53.002 1995 53.406 1996 53.876 1997 54.808 1998 55.61 1999 56.29 2000 56.984 2001 57.711 2002 57.946 2003 58.462 2004 58.818 2005 59.3 2006 59.96 2007 60.184 2008 60.641 2009 61.119 2010 61.209 2011 61.642 2012 61.695 2013 61.811 2014 62.25 2015 62.416 2016 62.952 2017 63.038 2018 63.2 2019 63.662 2020 62.891 2021 62.234 2022 62.97