Year annual % 1961 2.56381102590686 1962 2.59969435582652 1963 2.64958422880367 1964 2.67524021558525 1965 2.74635039458784 1966 2.84634316319423 1967 2.91320258928795 1968 2.93764508584771 1969 2.90299166995236 1970 2.86221657843084 1971 2.74689154282273 1972 2.66986839688998 1973 2.69217808128412 1974 2.68403404923439 1975 2.65635395653505 1976 2.57916355477329 1977 2.51079530919454 1978 3.08022604755108 1979 3.48641276944389 1980 3.06393041191748 1981 2.76608306113668 1982 2.73536091690952 1983 2.7470991708152 1984 2.97101447640962 1985 3.0331938715881 1986 2.95928285259829 1987 3.06503556376214 1988 3.12224280721746 1989 3.13791463486827 1990 3.28116908153439 1991 3.29964939656104 1992 3.01236457976563 1993 3.20523288626427 1994 4.76369168760456 1995 4.18422480056387 1996 1.90595041213998 1997 1.58195749260887 1998 2.36640881944012 1999 2.8603206446613 2000 2.89884128806625 2001 3.01946582164363 2002 3.05700023925831 2003 2.94405110630979 2004 2.98105657054334 2005 3.11546176922533 2006 3.1871715188242 2007 3.21553799022491 2008 3.19974361408747 2009 3.19424675479088 2010 3.24688069782067 2011 3.35179391507681 2012 3.35665613143748 2013 3.4091449670035 2014 3.44601675819051 2015 3.38939131180859 2016 3.46603464808537 2017 3.44276695760094 2018 3.27282723445499 2019 3.18628838899818 2020 3.22447844328183 2021 3.22252815991252 2022 3.19783510453186 2023 3.23230523620325