Year annual % 1961 2.47218570595133 1962 2.50812688252628 1963 2.54063933342381 1964 2.57054280877405 1965 2.59857351872816 1966 2.61831386165055 1967 2.63546367023201 1968 2.66113837008697 1969 2.66343834241463 1970 2.59896468109893 1971 2.53143364190133 1972 2.56849894141112 1973 2.67990390392211 1974 2.8178162778151 1975 2.922199270895 1976 3.09975431451856 1977 3.30139327889042 1978 3.38441855715898 1979 3.42076557974632 1980 3.43136564624015 1981 3.43212899936186 1982 3.42378237174167 1983 3.41552657412919 1984 3.4046617005856 1985 3.3925439742175 1986 3.32450318674489 1987 3.19724741732398 1988 3.09392231420842 1989 3.0430367091376 1990 3.00963173855987 1991 2.97261157298081 1992 2.94001714344113 1993 2.91423799736402 1994 2.90004472934947 1995 2.88896302293146 1996 2.85862109614102 1997 2.80461073747403 1998 2.75602860829703 1999 2.67948065791714 2000 2.53167345846883 2001 2.39380068808573 2002 2.3262995615241 2003 2.29314328165436 2004 2.26568934347868 2005 2.24285314785611 2006 2.24291000270575 2007 2.2422684243981 2008 2.23050143791026 2009 2.26712423337321 2010 2.35185573397427 2011 2.43624466471624 2012 2.50431283407337 2013 2.5393320797232 2014 2.54476579755385 2015 2.52650758971794 2016 2.48924408661005 2017 2.44276679046656 2018 2.39710667907408 2019 2.36010120913781 2020 2.3713876123354 2021 2.3817422996453 2022 2.29347735670131 2023 2.20546019496427