Year % 1961 2.206876308246451 1962 5.579788729769517 1963 3.2761668651329576 1964 1.7279375229593479 1965 2.265164054812211 1966 2.6207658722593496 1967 0.48366043712189677 1968 3.257356442273124 1969 1.0709088311784938 1970 1.6870626384900163 1971 1.961979577314894 1972 0.7832884968797197 1973 -1.503514177732883 1974 -6.019131824538135 1975 -5.338237024579568 1976 -3.598526355484449 1977 -1.3845682963964845 1978 1.0509097312130649 1979 0.45231913158385234 1980 -0.03415546952226798 1981 2.107507976573515 1982 1.416795281228061 1983 2.0500102361012433 1984 3.372151319732442 1985 7.390258658719111 1986 7.932094096491171 1987 7.527278694024499 1988 6.44108972053912 1989 6.619263857686919 1990 9.67270856641165 1991 10.092869400024828 1992 8.97038290484152 1993 8.473781143033932 1994 7.98605796893548 1995 8.022844372111335 1996 6.83251279377306 1997 5.819743005613423 1998 5.485434279156091 1999 6.062444730023366 2000 5.0374239651348836 2001 2.1130968649957165 2002 3.4249150091202454 2003 3.521734658530996 2004 3.6982016055137383 2005 3.3063398726425786 2006 2.375590567467343 2007 3.0574114756760915 2008 4.148913128692017 2009 1.0211349652366548 2010 6.057533613834459 2011 1.4457354548946135 2012 5.078166698560921 2013 6.353353796367187 2014 4.482137658988229 2015 6.236771423331203 2016 6.116716941461306 2017 1.5381073123631666 2018 3.3196529130074617 2019 1.5824650618413718