Year annual % 1961 3.211716341212744 1962 9.609161065471746 1963 10.583692936634113 1964 9.406448962826042 1965 10.887929416181716 1966 11.207042491958694 1967 9.362155579235806 1968 9.521158129175946 1969 13.51677681748856 1970 12.032693276605274 1971 17.060422538026423 1972 15.394466119710074 1973 19.496171346132503 1974 12.225338509259087 1975 14.051957652692495 1976 24.485570830148887 1977 19.163875440055335 1978 21.15282401776485 1979 17.71100518647909 1980 15.897673929397024 1981 17.450850801479657 1982 17.203932615410974 1983 16.887161429109895 1984 17.984401265849172 1985 16.8832410501987 1986 17.927459020766133 1987 16.31780172488538 1988 18.290618234615437 1989 15.730173307528258 1990 15.066613510956737 1991 18.316952275613254 1992 16.86249497025276 1993 17.0076625114277 1994 20.277728252280085 1995 11.011121101418727 1996 18.736274338553837 1997 17.65675429311411 1998 18.173014804276324 1999 17.149180478434626 2000 15.171707634844056 2001 14.320550688578795 2002 16.761164742930447 2003 13.033611087815592 2004 16.73233294774125 2005 15.599903899387241 2006 21.63314111558372 2007 22.27150287436189 2008 20.495209876878086 2009 17.995839217065328 2010 17.80217706389718 2011 16.137589344546505 2012 11.045696660166177 2013 14.83153000464959 2014 10.587381601221871 2015 10.617724556884639 2016 6.800954123580394 2017 10.431043710035224 2018 10.51961997520582 2019 10.510248428610742 2020 12.479137904316826 2021 11.297105670545875