Year annual % 1961 3.03033127728201 1962 3.04203773101787 1963 3.01890555338579 1964 2.94676444638627 1965 2.84608756023468 1966 2.70452747215214 1967 2.55633657403215 1968 2.46589974699603 1969 2.41802352363754 1970 2.40409940772393 1971 2.35926598575485 1972 2.33278300790499 1973 2.3879804780329 1974 2.43359463143772 1975 2.46392762759129 1976 2.48341266784309 1977 2.56007131418141 1978 2.62479563836581 1979 2.60544470412561 1980 2.61177455176428 1981 2.60569692601485 1982 2.59375588917813 1983 2.63596772165165 1984 2.71653205425924 1985 2.83077681264638 1986 2.93891981341768 1987 3.00329838283602 1988 3.01956255127948 1989 2.95463770412295 1990 2.8777395694329 1991 2.81665890726164 1992 2.78718569050924 1993 2.78577768971806 1994 2.78818789567647 1995 2.76003344637661 1996 2.7051266156806 1997 2.67135891326744 1998 2.60752186212402 1999 2.52672176362693 2000 2.54459366705921 2001 2.57014353027485 2002 2.51634742159783 2003 2.44260643657749 2004 2.3720084635771 2005 2.30336382151543 2006 2.23485955352487 2007 2.17608980403121 2008 2.08818532017883 2009 1.97892341382596 2010 1.75828740323151 2011 1.61104342924472 2012 1.61813131846729 2013 1.58743980435977 2014 1.55301827143161 2015 1.49940972361564 2016 1.4620698661924 2017 1.41536933264598 2018 1.31563682048248 2019 1.24151463105699 2020 1.19985962233223 2021 1.11985399101 2022 1.07936374148797 2023 1.08520231604055