Year years 1960 63.132 1961 63.575 1962 63.677 1963 63.832 1964 64.281 1965 64.38 1966 64.517 1967 64.882 1968 64.975 1969 65.083 1970 65.17 1971 65.22 1972 65.341 1973 65.668 1974 65.73 1975 50.806 1976 28.022 1977 55.309 1978 55.376 1979 55.436 1980 55.736 1981 55.872 1982 39.024 1983 53.585 1984 53.822 1985 54.015 1986 54.471 1987 57.352 1988 57.748 1989 57.627 1990 58.044 1991 69.744 1992 69.767 1993 69.796 1994 70.134 1995 70.762 1996 70.891 1997 71.124 1998 71.312 1999 71.893 2000 72.251 2001 72.558 2002 72.957 2003 73.657 2004 73.919 2005 74.223 2006 73.145 2007 74.719 2008 75.489 2009 75.826 2010 76.136 2011 76.407 2012 76.666 2013 76.782 2014 76.971 2015 77.234 2016 77.492 2017 77.599 2018 77.784 2019 77.251 2020 75.637 2021 72.847 2022 72.237