Year annual % 1961 5.908860749596126 1962 5.896993043811047 1963 5.877475196130173 1964 5.914758781626804 1965 5.718148574029594 1966 4.987876556030606 1967 2.6458447134234166 1968 2.6750601001516214 1969 2.669472156884312 1970 2.65599045187004 1971 2.6699032307431647 1972 2.725802079749016 1973 2.7886775253281257 1974 2.866744899657484 1975 4.114337479421482 1976 5.229177583414155 1977 4.827085440506146 1978 4.9614439238363195 1979 5.047972096136897 1980 5.136850822290652 1981 5.209931176863618 1982 5.2657884481484025 1983 5.290049725933896 1984 5.290481062655796 1985 5.268396663177547 1986 5.17342235382709 1987 4.777130420060711 1988 4.321473019938384 1989 4.177824324690226 1990 4.016594613559472 1991 3.8824507499169716 1992 3.7994467912129446 1993 3.6872556383144204 1994 3.5303736144774653 1995 3.3171486447084613 1996 3.1413544377514695 1997 3.0282985315412336 1998 2.8380949305988685 1999 2.769464534393413 2000 2.7481123046651206 2001 2.6907037793395636 2002 2.640071820734245 2003 2.619353160117175 2004 2.6470662285032995 2005 2.5761615389916677 2006 2.6294119880867726 2007 2.789987447481049 2008 2.8486243884222255 2009 2.892792881939079 2010 2.921480595899897 2011 2.923621640206755 2012 2.9332583437715716 2013 2.9212994166614354 2014 2.901821798299828 2015 2.888877931503774 2016 2.852142556740059 2017 2.783424625310664 2018 2.700947183190818 2019 2.607529823881084 2020 2.4729887519154095 2021 2.371249675400791 2022 2.3140935770003614 2023 2.2151788720839356