Year annual % 1961 2.32430259481842 1962 2.39216569535363 1963 2.44155017473533 1964 2.47516842793677 1965 2.50010652316175 1966 2.51113215271419 1967 2.51449196822002 1968 2.51549789522301 1969 2.52731228666856 1970 2.56138396509594 1971 2.59698454535762 1972 2.61466037807186 1973 2.62608775833674 1974 2.63151194650023 1975 2.62905200962032 1976 2.63839120415611 1977 2.65930944462214 1978 2.6696888149444 1979 2.67744128648283 1980 2.69915839211273 1981 2.72533942483232 1982 2.7358158124778 1983 2.74705736558148 1984 2.7282829316494 1985 2.64892301829846 1986 2.61744797669467 1987 2.569479931273 1988 2.52689904576332 1989 2.43579368450095 1990 2.2497645204013 1991 -5.28818555159151 1992 -5.96418551668818 1993 3.0887728057642 1994 3.03612930618359 1995 5.46458079635181 1996 4.83450479218313 1997 1.2067841093189 1998 1.35198753803808 1999 1.44145869854362 2000 1.53299543125693 2001 2.84467152232301 2002 3.41382758677749 2003 4.07554152440981 2004 4.0529646475642 2005 2.45208243654581 2006 1.69340467080078 2007 1.58711319244676 2008 2.68430517830464 2009 2.56543695688394 2010 2.04894664970192 2011 1.88330360533393 2012 1.39398056061833 2013 1.33675062099253 2014 0.817492473750786 2015 0.49767257206961 2016 0.754064581294597 2017 0.935971649156141 2018 1.41594960093608 2019 1.53927354632927 2020 1.61739994313834 2021 1.7961013366299 2022 1.74475945969517 2023 1.74549257972489