Year years 1960 30.596 1961 30.976 1962 31.361 1963 31.67 1964 32.011 1965 32.759 1966 33.403 1967 34.139 1968 34.624 1969 35.098 1970 35.549 1971 36.103 1972 36.697 1973 37.368 1974 35.362 1975 20.879 1976 21.736 1977 20.517 1978 18.46 1979 18.991 1980 23.599 1981 24.538 1982 25.564 1983 26.279 1984 28.011 1985 28.163 1986 28.686 1987 29.8 1988 30.01 1989 42.984 1990 43.532 1991 43.501 1992 44.803 1993 45.765 1994 46.792 1995 46.537 1996 47.283 1997 47.879 1998 47.503 1999 42.826 2000 57.158 2001 57.929 2002 58.705 2003 59.42 2004 60.129 2005 60.839 2006 61.588 2007 62.208 2008 62.783 2009 63.314 2010 63.769 2011 64.167 2012 64.522 2013 64.84 2014 65.171 2015 65.539 2016 65.869 2017 66.188 2018 66.468 2019 66.721 2020 66.837 2021 66.1 2022 67.435