Year annual % 1961 0.705711483663754 1962 0.679995399829919 1963 0.706977468183943 1964 0.556315625077213 1965 0.333374795369662 1966 0.374800826434961 1967 0.541550205582204 1968 0.448972197973546 1969 -0.0580308405654956 1970 -0.378718237915962 1971 0.126203705860136 1972 0.595195266324646 1973 0.567909197939041 1974 0.523542995771684 1975 0.443863075666863 1976 0.30144863871956 1977 0.279738313043981 1978 0.287122369568676 1979 0.25557902782611 1980 0.311078415926419 1981 0.426515644912231 1982 0.560285843941572 1983 0.595991320809624 1984 0.534342930873442 1985 0.41706890447956 1986 0.324794895907026 1987 0.283626731803862 1988 0.290689051012441 1989 0.361018799003539 1990 0.443382073914297 1991 0.546172018187903 1992 0.561909850746084 1993 0.483854088858285 1994 0.431048902829755 1995 0.381655333457214 1996 0.328037913627481 1997 0.297377330426395 1998 0.265472962436301 1999 0.232116249119004 2000 0.2076065154133 2001 0.227687341886374 2002 0.242381050233372 2003 0.238457240068217 2004 0.290350361518584 2005 0.342248594286999 2006 0.383777136305104 2007 0.425429832100631 2008 0.465549284507694 2009 0.478246393482911 2010 0.457494535465831 2011 0.463558707499131 2012 0.475809486683209 2013 0.460723772785295 2014 0.413560207519414 2015 0.329383885818507 2016 0.287421401687637 2017 0.234670531705453 2018 0.132641040791912 2019 0.110191690491055 2020 0.143641197212847 2021 0.207288594407348 2022 0.271944526506117 2023 0.505513909563998