Year annual % 1961 3.63482787677081 1962 3.58081641449101 1963 3.5044683593811 1964 3.41185905780376 1965 3.30308772209251 1966 3.18586019855954 1967 3.06170198844071 1968 2.90403220393468 1969 2.78686233527351 1970 2.71636306038062 1971 2.64767274255807 1972 2.59328555465073 1973 2.55958628696517 1974 2.55830068574315 1975 2.57155211691094 1976 2.60303887566708 1977 2.6445292256157 1978 2.68554030631481 1979 2.72041089468848 1980 2.73110989940276 1981 2.73856861732179 1982 2.76028759661915 1983 2.77410685602989 1984 2.7703110963721 1985 2.75319653423939 1986 2.71886328639952 1987 2.65920370774586 1988 2.59431605634214 1989 2.55060236009875 1990 2.54138328976122 1991 2.53734226281102 1992 2.51561993414361 1993 2.48055361450883 1994 2.43045420119032 1995 2.37065492148785 1996 2.30683799579665 1997 2.24971306873938 1998 2.1691556368856 1999 2.07208096201444 2000 1.97358823214158 2001 1.84330854695316 2002 1.69774908835068 2003 1.58793253810516 2004 1.52086528848105 2005 1.47252758666781 2006 1.43284202712965 2007 1.40273700394929 2008 1.38455388597677 2009 1.35039395502168 2010 1.2873898093698 2011 1.24002656207939 2012 1.20358030533586 2013 1.1532718484809 2014 1.09494595424381 2015 1.04634340433544 2016 1.01547072688832 2017 0.978713315995535 2018 0.934615300864476 2019 0.865128346659953 2020 0.755771068349343 2021 0.600406861056438 2022 0.520031291578434 2023 0.603176926750417