Year annual % 1961 2.58971462502766 1962 2.75638096247026 1963 2.89284134676927 1964 2.94293267810448 1965 3.01184662945533 1966 3.07600131851588 1967 3.13061883762921 1968 3.17848609103675 1969 3.22965628611938 1970 3.2638610076405 1971 3.27246341405865 1972 3.27786465967249 1973 3.2894133902984 1974 3.29326166729264 1975 3.29760614895153 1976 3.30856489980186 1977 3.31371321030012 1978 3.31465470767433 1979 3.28443762924931 1980 3.22888129079952 1981 3.17221330874452 1982 3.11447910873238 1983 3.080064547601 1984 3.05185216084329 1985 3.00915242732183 1986 2.97334339875952 1987 2.93651926472252 1988 2.8810987695454 1989 2.82485287209837 1990 2.58173992694972 1991 1.64599614396289 1992 -3.90943185767227 1993 -4.70773534799775 1994 0.0809904678960111 1995 1.19681518857701 1996 1.87004876817793 1997 1.72843740815916 1998 1.86199682422406 1999 2.45497568951543 2000 2.80057018423756 2001 2.69277829428078 2002 2.58776329516912 2003 2.48546106253177 2004 2.39210919099831 2005 2.03035343996667 2006 1.48695338651854 2007 1.23319303054383 2008 1.18468503010311 2009 1.14473127595882 2010 1.11717717159158 2011 1.10160983275966 2012 1.08946783207717 2013 1.06812304057562 2014 1.0193598434941 2015 0.934969649654716 2016 0.868973710626164 2017 0.844692720380736 2018 0.787111572078005 2019 0.701252583573764 2020 0.655471789302584 2021 0.642586172837449 2022 0.63707753130368 2023 0.63304453326495