Year annual % 1961 1.53260613603588 1962 1.0576534413945 1963 0.989440824312753 1964 0.863701746923404 1965 0.814360720819285 1966 0.84216219675292 1967 0.820473288801262 1968 0.754994869076767 1969 0.688428297949465 1970 0.62350265585546 1971 0.561618697250031 1972 0.496427968345348 1973 0.475228591612223 1974 -0.326332363271116 1975 -0.557065744166412 1976 0.600689675744346 1977 1.15623812596797 1978 1.14528107184778 1979 1.14348057009352 1980 1.14232983393901 1981 1.14791120983013 1982 1.30940422806958 1983 1.60293635705018 1984 1.7098769599148 1985 1.65175024334007 1986 1.59747416196886 1987 1.54494296244591 1988 1.49743207223701 1989 1.448208087335 1990 1.39304413756299 1991 1.33048818808073 1992 1.41289166336657 1993 1.90116193072313 1994 2.2100598397478 1995 2.10616492997985 1996 2.02477424691791 1997 1.95929934714224 1998 1.89716036586914 1999 1.83511264888196 2000 1.77009330000432 2001 1.73474490066302 2002 1.78369248341346 2003 1.83163728954308 2004 1.81616594339173 2005 1.78801171115289 2006 1.75641313375661 2007 1.73158929128947 2008 1.70962168593317 2009 1.68691516238933 2010 1.67026099599159 2011 1.35400253526204 2012 0.996688012391421 2013 0.8962308711661 2014 0.855564798922502 2015 0.870039642466962 2016 0.888918593369278 2017 0.884479029885329 2018 0.849324982193926 2019 0.817517719721429 2020 0.705573414651573 2021 0.535999429698235 2022 0.585013504929064 2023 0.688799542570149