Year annual % 1961 2.97026938454193 1962 3.02968927533045 1963 3.04931689621707 1964 3.14910223263789 1965 3.20206449418141 1966 3.05914831424818 1967 3.00976664570999 1968 3.0384792623554 1969 3.02957984670179 1970 3.04505280068195 1971 3.16656551369303 1972 3.27379854127154 1973 3.36259922979227 1974 3.78771106636506 1975 4.13375977795885 1976 4.1253366659246 1977 4.18538999131019 1978 4.26172980866171 1979 4.26696918582142 1980 4.2923865207415 1981 4.28935799737969 1982 4.0773141132874 1983 3.28472761808475 1984 2.27895833492794 1985 1.81665518839006 1986 1.87930569589589 1987 1.71039683271081 1988 1.09766648080682 1989 1.28674952805151 1990 1.78038955394371 1991 1.70566333632953 1992 1.50971890053507 1993 1.74407304866166 1994 2.40893107478887 1995 2.55250639227257 1996 2.42481159995041 1997 2.45109662763757 1998 2.3231892056128 1999 2.38850091216307 2000 2.55963690837227 2001 2.43590785577774 2002 2.28583965848042 2003 2.21912557576201 2004 2.25392586427754 2005 2.42945361033328 2006 2.64703640708656 2007 2.78996436965565 2008 2.76377910390166 2009 2.71626568948597 2010 2.37468258916878 2011 1.9944775499975 2012 2.12762901437903 2013 2.3357525902736 2014 2.77449286124806 2015 3.10751167131043 2016 3.11054531285464 2017 3.25461617065729 2018 3.19148702209797 2019 2.89358996893094 2020 2.75677878454575 2021 2.70104593999388 2022 2.63061426078782 2023 2.6001891699622