Year annual % 1961 2.3797012269259 1962 2.31242006400112 1963 2.38650385787809 1964 2.45821545233956 1965 2.51791971765606 1966 2.58539639564733 1967 2.65320120242553 1968 2.69973737137522 1969 2.7278332638243 1970 2.76002653560861 1971 2.64293253752341 1972 2.64348946760201 1973 2.80164442306919 1974 2.85762988601594 1975 2.94612675483924 1976 3.04151169440751 1977 3.11232079319945 1978 3.17633071983058 1979 3.44063933128741 1980 4.07154578640826 1981 4.42312479149621 1982 4.13542839724215 1983 3.63597146977849 1984 3.15935942130459 1985 3.26273876924285 1986 3.53730585510265 1987 3.54659790712452 1988 3.50310414413814 1989 3.37181635871608 1990 3.29747116559875 1991 3.23064337372364 1992 2.62588681084768 1993 2.55855603034947 1994 2.90337795268012 1995 2.95211131596515 1996 3.04613837555745 1997 2.94060702615898 1998 2.89123826209315 1999 2.8584443558606 2000 3.07555291166784 2001 3.09207918437975 2002 2.50885975954029 2003 2.1893881210377 2004 2.23514920732307 2005 2.15849215504399 2006 2.0985131417675 2007 2.14152397156301 2008 2.17888921699852 2009 2.2291625346925 2010 2.25257934512803 2011 2.11083457768435 2012 1.7979754297027 2013 1.53689764905925 2014 1.40918297342086 2015 1.29655172364692 2016 1.20405567252781 2017 1.32813543357738 2018 1.5371724033626 2019 1.6079813474837 2020 1.73302782045863 2021 1.83406208240793 2022 1.89324559780014 2023 1.9571034315941