Year % 1978 10.774631330248107 1979 -1.0611457457749522 1980 4.476508260900934 1981 5.11823674143201 1982 7.774707244395978 1983 7.320986685084805 1984 7.9470999203981805 1985 8.681673584786642 1986 9.093224145088236 1987 6.560180094154518 1988 7.638632995945092 1989 7.43584324824212 1990 5.269526998274231 1991 3.6247165957506193 1992 9.132749405876595 1993 5.814776512130363 1994 4.337109737579386 1995 5.864178109081859 1996 7.792994300298666 1997 6.90957899531884 1998 5.121276328772201 1999 9.191247322389653 2000 8.342610831409267 2001 8.591449296371632 2002 7.907177188974632 2003 7.307881160384139 2004 4.9101283033461955 2005 4.855145171866085 2006 2.570606701768297 2007 5.681844064537108 2008 3.7717562496539365 2009 4.808592107665974 2010 -1.9838592213986646 2011 1.3179808619193742 2012 2.4735204887934725 2013 3.865992862721591 2014 6.695176090464942 2015 7.556488413558984 2016 6.232711414763854 2017 5.32760886239731 2018 5.36166638957659 2019 6.894875427255142 2020 4.135999577896659 2021 0.3169451441797755 2022 1.7046109285225284