Year years 1960 69.25460975609757 1961 69.73839024390244 1962 69.46231707317075 1963 69.70978048780489 1964 70.61924390243904 1965 70.59748780487806 1966 70.7689268292683 1967 70.92978048780488 1968 70.81278048780489 1969 70.97802439024392 1970 70.74448780487806 1971 71.01170731707319 1972 70.84931707317075 1973 71.00065853658538 1974 70.85468292682927 1975 70.45709756097561 1976 70.39682926829269 1977 70.28902439024392 1978 70.08173170731708 1979 69.93363414634146 1980 69.92770731707319 1981 69.90751219512197 1982 70.0769024390244 1983 69.7948536585366 1984 69.56319512195124 1985 70.99268292682929 1986 71.54951219512196 1987 70.99024390243902 1988 71.34146341463415 1989 71.48292682926831 1990 70.83658536585365 1991 70.37804878048782 1992 70.0219512195122 1993 68.97073170731707 1994 68.76829268292683 1995 68.4609756097561 1996 68.51219512195122 1997 68.4609756097561 1998 68.40731707317074 1999 67.90731707317074 2000 68.91219512195123 2001 68.50731707317074 2002 68.05609756097562 2003 68.55365853658539 2004 68.95609756097562 2005 68.85121951219512 2006 69.40487804878049 2007 70.20731707317074 2008 70.45609756097562 2009 70.40731707317074 2010 70.40487804878049 2011 70.55365853658537 2012 71.96585365853657 2013 72.47073170731707 2014 72.97073170731709 2015 73.62439024390245 2016 73.8268292682927 2017 74.12926829268294 2018 74.17560975609757 2019 74.2268292682927 2020 72.45721951219514 2021 72.37068292682928 2022 73.11146341463416