Year annual % 1961 24.025591998823355 1962 19.78654017195375 1963 13.624888624888627 1964 3.2760460911803784 1965 6.392761478919285 1966 15.423043374831497 1967 21.338279747183293 1968 10.53957649190352 1969 11.359387404922273 1970 12.572874144770886 1971 15.750926975760732 1972 13.975591030630344 1973 23.512651367338723 1974 16.306010380883126 1975 13.798939289410143 1976 28.052742755922665 1977 28.543688602201446 1978 24.245772441237147 1979 12.441032410463055 1980 20.61516787978399 1981 17.420912608560528 1982 18.487343631387446 1983 52.99006828971334 1984 17.947658579006312 1985 12.454131232796025 1986 1.6890144804639844 1987 11.672523399172999 1988 23.26060012750992 1989 30.24139029193002 1990 22.398112055090937 1991 17.71649744142714 1992 13.109483215385985 1993 28.14577153827205 1994 26.73477784962055 1995 23.874140390550373 1996 23.731508063642924 1997 23.107655416302723 1998 8.566311267776864 1999 16.882184699321137 2000 8.120764926906624 2001 9.985692427480576 2002 9.96845059499668 2003 4.287276009672414 2004 10.723320128636216 2005 6.8422007098892905 2006 23.453614135033988 2007 9.605706455443643 2008 10.04090309034629 2009 8.63839150729624 2010 10.897082770600688 2011 5.306749762856609 2012 6.977796231858996 2013 29.329502551069016 2014 12.437500484562976 2015 9.195824605523919 2016 13.326273033800822 2017 11.423124947866135 2018 8.999145744784798 2019 9.843921639096688 2020 8.657732058856666 2021 7.9802684339455405 2022 7.8203392393223545