Year annual % 1961 2.96277856647304 1962 2.95268460253087 1963 2.927161985058 1964 2.92316532163094 1965 2.92202776542478 1966 2.89786246170878 1967 2.87416385545982 1968 2.8560660720418 1969 2.84388179977747 1970 2.6041998100498 1971 2.54503571421173 1972 2.69810393632063 1973 2.64001986001968 1974 2.5723906934301 1975 2.52038740807264 1976 2.46470311736746 1977 2.48238831966364 1978 2.51886748413374 1979 2.4970683288076 1980 2.50780755368984 1981 2.48391657997361 1982 2.43508579524966 1983 2.4330149256554 1984 2.40740717354434 1985 2.3620742408617 1986 2.31183594285629 1987 2.26489768953194 1988 2.25975036452914 1989 2.24715200247878 1990 2.21710522088361 1991 2.12084332741883 1992 2.03486931683517 1993 2.00446004559178 1994 1.97650334441666 1995 1.92355612770439 1996 1.85695289229942 1997 1.82243949325095 1998 1.7695187906283 1999 1.6670604009319 2000 1.52044227070086 2001 1.34331954460691 2002 1.17608515721159 2003 1.05113533724533 2004 0.974731754515074 2005 0.904184155760706 2006 0.827239266792745 2007 0.769759369616088 2008 0.716987182658426 2009 0.702724346623641 2010 0.756357202975091 2011 0.845382115888711 2012 0.918055908591097 2013 0.967486220265649 2014 1.04365112789631 2015 1.17223066396866 2016 1.36122543775229 2017 1.50694618507609 2018 1.87582164020533 2019 1.90972560807882 2020 1.45140240084226 2021 1.22566025209601 2022 0.986112053718798 2023 0.886323861618286