Year years 1960 56.22304878048781 1961 57.79982926829269 1962 57.523341463414646 1963 56.69934146341465 1964 58.9859268292683 1965 60.0019268292683 1966 61.959853658536595 1967 62.12785365853659 1968 62.863780487804874 1969 63.02656097560977 1970 63.719390243902446 1971 64.61760975609756 1972 65.54914634146343 1973 65.93612195121952 1974 66.592 1975 66.98778048780488 1976 67.74556097560976 1977 68.44343902439026 1978 69.35914634146341 1979 69.65021951219512 1980 69.24712195121953 1981 69.81048780487806 1982 69.95556097560977 1983 69.48268292682928 1984 70.02175609756098 1985 70.08207317073172 1986 70.383 1987 70.37660975609757 1988 70.81943902439025 1989 71.1368292682927 1990 71.23380487804877 1991 71.84443902439025 1992 71.24407317073171 1993 71.92529268292682 1994 71.69268292682928 1995 71.84878048780489 1996 72.49512195121952 1997 72.44634146341464 1998 72.29756097560977 1999 72.79024390243904 2000 72.94634146341465 2001 73.43658536585367 2002 73.03902439024391 2003 73.24146341463415 2004 73.59756097560977 2005 73.69756097560976 2006 73.89512195121952 2007 73.80000000000001 2008 74.4 2009 74.44634146341464 2010 74.99756097560976 2011 75.1 2012 74.90243902439026 2013 75.4 2014 75.45121951219514 2015 75.40243902439025 2016 75.4 2017 75.95365853658537 2018 76.64878048780488 2019 76.60243902439025 2020 74.39512195121951 2021 73.24634146341464 2022 74.4248780487805