Year annual % 1961 2.82854210231362 1962 2.82400739564471 1963 2.81672759393385 1964 2.82650721802994 1965 2.85878888473469 1966 2.9042134320401 1967 2.94125300076171 1968 2.95233288307507 1969 2.94810450750895 1970 2.94807856024493 1971 2.95231652493326 1972 2.95323687355495 1973 2.94715142248462 1974 2.87896324280468 1975 2.74133641512569 1976 2.6059051190583 1977 2.42353435366142 1978 2.3261812112817 1979 2.38695806475924 1980 2.47422555657384 1981 2.56437222074908 1982 2.63687199552555 1983 2.68453608445209 1984 2.71602779935722 1985 2.78197014177237 1986 2.87483360565634 1987 2.92152135159267 1988 2.90674570037734 1989 2.88470643804651 1990 2.88311000862987 1991 2.85544396696351 1992 2.80045967350139 1993 2.74627496579219 1994 2.65396577748329 1995 2.53020035291858 1996 2.41189015578578 1997 2.32607796078074 1998 2.29340313946298 1999 2.31639981025849 2000 2.35349186373024 2001 2.38007633836581 2002 2.41498169831971 2003 2.45996800523196 2004 2.50033904791585 2005 2.54126351828797 2006 2.60233440516001 2007 2.63281190597884 2008 2.63754388814397 2009 2.67674749775798 2010 2.71070159961371 2011 2.72203680436678 2012 2.72697235540654 2013 2.71181928883915 2014 2.71905100988297 2015 2.72463609047466 2016 2.7154429589038 2017 2.7179778377713 2018 2.71464328183934 2019 2.69763115886709 2020 2.68438184925041 2021 2.64538054494311 2022 2.57217015290678 2023 2.54699595340171