Year years 1960 41.299 1961 41.747 1962 42.134 1963 41.049 1964 42.932 1965 43.329 1966 43.622 1967 44.171 1968 44.589 1969 45.034 1970 45.5 1971 45.869 1972 46.151 1973 46.441 1974 46.715 1975 46.992 1976 47.353 1977 47.624 1978 47.862 1979 48.22 1980 48.621 1981 48.994 1982 49.316 1983 49.692 1984 50.009 1985 50.272 1986 50.515 1987 50.97 1988 51.365 1989 51.489 1990 51.827 1991 51.966 1992 52.489 1993 53.002 1994 53.37 1995 54.133 1996 54.647 1997 55.023 1998 55.562 1999 56.272 2000 56.608 2001 56.713 2002 57.019 2003 57.57 2004 56.715 2005 58.265 2006 58.521 2007 58.842 2008 59.029 2009 59.429 2010 45.758 2011 59.202 2012 59.857 2013 60.086 2014 60.387 2015 60.617 2016 60.661 2017 61.087 2018 61.231 2019 61.314 2020 61.131 2021 60.399 2022 60.892