Year years 1960 64.187 1961 64.804 1962 65.424 1963 62.282 1964 62.79 1965 67.052 1966 67.495 1967 67.917 1968 68.273 1969 68.49 1970 68.927 1971 69.33 1972 69.811 1973 70.163 1974 55.23 1975 70.518 1976 71.04 1977 71.302 1978 71.767 1979 71.895 1980 71.95 1981 71.941 1982 71.981 1983 72.311 1984 72.255 1985 72.647 1986 72.651 1987 73.089 1988 73.129 1989 73.48 1990 73.539 1991 73.716 1992 74.177 1993 74.65 1994 74.72 1995 75.133 1996 75.522 1997 75.841 1998 76.182 1999 76.295 2000 76.568 2001 76.989 2002 77.487 2003 77.788 2004 77.944 2005 78.101 2006 78.371 2007 78.81 2008 78.981 2009 79.401 2010 79.665 2011 79.999 2012 80.109 2013 80.402 2014 80.771 2015 80.966 2016 81.056 2017 81.328 2018 81.382 2019 81.397 2020 81.391 2021 81.203 2022 81.889