Year annual % 1967 13.739897134459955 1968 17.2609819121447 1969 9.156015866020272 1970 12.021802765721207 1971 18.23752027392323 1972 17.729766803840878 1973 18.23154351555167 1974 22.148644949356694 1975 24.44168539854642 1976 25.1031029949394 1977 20.155183830938878 1978 12.575029652437491 1979 46.93656013537243 1980 26.894383845407273 1981 18.09324307355107 1982 19.52130770383331 1983 17.78830989218961 1984 3.6807267383975226 1985 30.432954187983245 1986 27.71914770462629 1987 32.064434183351985 1988 32.83418548191674 1989 32.054718774821566 1990 41.86351235353696 1991 30.078321831095256 1992 40.59059910120846 1993 39.22200680955958 1994 35.34673004745102 1995 33.00780977811221 1996 8.404668747237086 1997 12.851310292442081 1998 10.77751494225349 1999 18.553940470348127 2000 14.797068901792972 2001 34.229267961614624 2002 25.55625038609457 2003 17.968742152358857 2004 13.492868160795119 2005 34.78186496048699 2006 21.495876011428834 2007 20.508125533712963 2008 19.846916679734075 2009 17.71555702382182 2010 25.42692369100242 2011 18.23953206372849 2012 12.48554432558084 2013 9.965542218654997 2014 15.567262883378119 2015 18.809151137133604 2016 3.448067219905864 2017 8.027227793269967 2018 4.487796720130005 2019 9.641209954499097 2020 5.677291562245816 2021 15.499292263208982 2022 11.638303069092332 2023 14.055347043098775