Year annual % 1961 3.1033343319455895 1962 3.012855315335969 1963 5.0137992732698535 1964 13.557594354150936 1965 12.277961360550677 1966 9.316906497438211 1967 10.1151075088395 1968 18.295793692870447 1969 8.138430476350749 1970 11.981089943679407 1971 6.6403424278692995 1972 7.129489774752699 1973 12.575532138610797 1974 15.233435329526685 1975 22.19156776955728 1976 29.712922577851458 1977 35.74134122096271 1978 63.73821735307726 1979 76.34984545433016 1980 37.92997311585512 1981 65.33058093606556 1982 66.66333314455676 1983 107.39685323912965 1984 108.47753323460356 1985 165.73497247931135 1986 68.36351395652088 1987 85.64964330407511 1988 586.2787311315263 1989 2572.325926209786 1990 6261.2395586102975 1991 378.0405787097723 1992 69.26061762375525 1993 46.384682865326965 1994 26.68824123494049 1995 13.578797877150222 1996 9.687741961214797 1997 7.283131128656123 1998 5.37109035742958 1999 2.9345454117467966 2000 3.5247200388048014 2001 0.4552483029020493 2002 0.10901702378551192 2003 1.8037246653412922 2004 6.279038577105055 2005 3.5037224004985887 2006 7.656248078896823 2007 1.490675954539043 2008 1.1032762920285535 2009 2.063698334406155 2010 5.710728594075221 2011 6.745787124756902 2012 1.202584940227382 2013 1.0572343514957652 2014 2.4324410850177856 2015 2.6905209007433086 2016 3.0808826903773365 2017 3.6156582610597354 2018 2.277415317621333 2019 1.8722162677549505 2020 3.7191711966950436 2021 10.083101828505477 2022 4.766461936701177 2023 6.566343631344182