Year annual % 1961 20.48469387755102 1962 18.46284141435528 1963 50.47363717605005 1964 -15.96389119847963 1965 4 1966 12.748029355803208 1967 12.644648023143684 1968 4.794007490636704 1969 17.635045440620853 1970 12.769097222222223 1971 7.766915556924024 1972 18.664285714285715 1973 23.59597905254921 1974 35.2651828763454 1975 18.76575214229135 1976 24.949978778875888 1977 42.857142857142854 1978 27.489809782608692 1979 30.178776010444142 1980 29.367580843225543 1981 41.99164675916404 1982 41.17089965070221 1983 22.743739295833564 1984 19.565007716049383 1985 64.24259535621614 1986 27.908842356870384 1987 36.4875588777391 1988 32.82505743892718 1989 53.31690647989946 1990 48.751813220971194 1991 67.54988824290605 1992 139.788405149079 1993 103.91974048189614 1994 51.175537040185915 1995 72.68036147905973 1996 65.6174866868252 1997 38.0038979880788 1998 29.93059588489772 1999 23.466761161052652 2000 36.85801418831694 2001 24.514622555747607 2002 30.432735877643314 2003 28.15982806050367 2004 30.165305329067433 2005 43.41737713632693 2006 32.1888104507858 2007 10.768279769383705 2008 16.341662973358364 2009 23.787098763311914 2010 26.27251630283102 2011 17.72009451201858 2012 39.14060272619505 2013 13.073585439373703 2014 16.990136238176962 2015 20.876939079248206 2016 28.258887869659056 2017 68.78463058670258 2018 111.82632680513052 2019 60.078929628333746 2020 87.99138313020343