Year annual % 1961 3.1098509758004 1962 3.12553269779522 1963 3.15071857358442 1964 3.08501275877978 1965 2.9856452129641 1966 2.80624867654198 1967 2.51274747948943 1968 2.26811147090461 1969 2.14548604213848 1970 2.04528346551456 1971 1.94556986353039 1972 1.82670805532957 1973 1.68775643327703 1974 1.61137046530022 1975 1.66504153096409 1976 1.85877646358817 1977 2.13888629021089 1978 2.36172243321419 1979 2.45458893491966 1980 2.46949784674888 1981 2.45918804888992 1982 2.44286020771579 1983 2.42628058798333 1984 2.41694657402892 1985 2.35055904777605 1986 2.06752532908356 1987 1.61880236236793 1988 1.2628298852371 1989 1.08440864512957 1990 0.994899825536046 1991 0.562463230476735 1992 0.257938885422665 1993 0.296816893960149 1994 0.203164498258415 1995 0.182306473098269 1996 0.540288729079706 1997 1.00356220718326 1998 1.15847943080594 1999 1.15735741455603 2000 1.09752051437681 2001 1.05280543999033 2002 1.01360189605196 2003 0.985257329508455 2004 0.972529404319471 2005 0.94499091797119 2006 0.928331143605677 2007 0.853009376352656 2008 0.680664088099223 2009 0.517432196093315 2010 0.419141607071656 2011 0.351360475814814 2012 0.297238780271001 2013 0.262426487072664 2014 0.230397589525045 2015 0.178965105930181 2016 0.127589742794731 2017 0.0705348376627642 2018 -0.00250269992369218 2019 -0.0577971466911964 2020 0.212846220439299 2021 0.45397664568484 2022 0.556091460082176 2023 0.708309568380842