Year annual % 1961 5.653382832424578 1962 7.081499409749881 1963 7.088562032000796 1964 7.059328552174557 1965 7.052338568731127 1966 7.011662729829133 1967 7.03709767576184 1968 7.017110154491791 1969 6.895236938724637 1970 6.501174522255326 1971 5.20399854395982 1972 5.379633050403882 1973 6.5188985658703045 1974 7.973992576702151 1975 10.87943763035991 1976 10.65252361819257 1977 10.600269562549228 1978 10.605493772068774 1979 10.495063977570073 1980 10.498013586872624 1981 8.817186284486379 1982 5.315997395347156 1983 5.324820826001385 1984 5.243655883045896 1985 5.083024132087538 1986 4.893082457964806 1987 4.731451937332783 1988 4.65539513301814 1989 4.591186309026437 1990 4.583963888899985 1991 4.162852569267956 1992 3.5681298941755535 1993 3.6233922231001774 1994 3.6296649763317257 1995 3.5635823157969835 1996 3.449107980942913 1997 3.468605378431965 1998 3.5555154513716407 1999 3.583953432873768 2000 3.5639666321410335 2001 4.0215485262066375 2002 4.560228225960112 2003 4.428774162403604 2004 4.319324358554943 2005 4.14458215704186 2006 3.817223870193573 2007 3.634036977038244 2008 3.4436910718805196 2009 3.405919775717228 2010 3.644549781215739 2011 3.692842583391135 2012 3.673378508357885 2013 3.6423755402030458 2014 3.577997448042089 2015 3.4699490189497864 2016 3.464608061794551 2017 3.4347258719703295 2018 3.296925085757067 2019 3.2013945716686725 2020 3.18709422690114 2021 3.143603061184201 2022 3.020051347031416 2023 2.9281517047064933