Year years 1960 45.121 1961 46.083 1962 47.226 1963 47.5 1964 48.52 1965 47.858 1966 49.453 1967 49.707 1968 49.982 1969 50.066 1970 44.485 1971 22.302 1972 50.594 1973 50.793 1974 50.184 1975 51.245 1976 51.894 1977 52.21 1978 52.354 1979 52.586 1980 52.848 1981 53.215 1982 53.518 1983 53.961 1984 54.331 1985 54.439 1986 55.152 1987 55.516 1988 55.62 1989 56.135 1990 57.211 1991 55.217 1992 58.192 1993 58.575 1994 59.113 1995 59.905 1996 60.341 1997 61.526 1998 63.877 1999 66.394 2000 65.472 2001 65.665 2002 65.74 2003 65.648 2004 66.038 2005 66.005 2006 65.911 2007 65.417 2008 65.597 2009 66.111 2010 67.165 2011 67.339 2012 67.605 2013 67.108 2014 67.876 2015 68.498 2016 69.085 2017 69.822 2018 70.889 2019 70.713 2020 70.187 2021 70.599 2022 71.514