Year annual % 1971 5.622345943225412 1972 5.577384055925734 1973 9.964066763623862 1974 4.148113882412247 1975 4.822183506165501 1976 6.199211933187925 1977 4.613925843015636 1978 2.16033425878544 1979 7.634745751572723 1980 6.236781769770275 1981 8.637631787008203 1982 29.66566311597532 1983 29.319178168199755 1984 25.24644754362278 1985 19.00004672624054 1986 69.6611853546114 1987 27.259990113419065 1988 21.6536391309226 1989 22.315573420832663 1990 17.279181168489515 1991 25.818670567109805 1992 26.22021362608504 1993 0.6737572773863718 1994 1.4280016398634103 1995 5.951338300531589 1996 1.5459682370531738 1997 1.434126666367817 1998 3.3246404448857447 1999 4.227675306702096 2000 6.300123958362519 2001 1.7524263185358109 2002 0.4327723766588605 2003 15.910696557568443 2004 16.52158332333677 2005 27.390845372339484 2006 37.58404182185515 2007 13.618875942629245 2008 16.705124399657407 2009 1.7710292430526096 2010 16.10261759621001 2011 8.99929083812954 2012 11.515970683051748 2013 4.329351573956927 2014 2.6158966829377306 2015 2.9722893544020366 2016 5.668948450346804 2017 10.35650236127583 2018 7.059084425711902 2019 9.402907657988209 2020 4.6939380289855706 2021 11.499999999459149 2022 10.992148998027119 2023 7.393203026553621