Year | Value | 2021 | 79.853502556136 | 2020 | 80.317362323732 | 2019 | 81.706015175639 | 2018 | 81.484021705753 | 2017 | 81.395140432546 | 2016 | 81.394540738942 | 2015 | 81.469406938962 | 2014 | 81.560658221083 | 2013 | 81.464125473387 | 2012 | 81.460520097505 | 2011 | 81.355614619656 | 2010 | 81.250985765617 | 2009 | 81.139150746157 | 2008 | 80.840368703527 | 2007 | 80.826746306382 | 2006 | 80.555636185557 | 2005 | 80.337029270351 | 2004 | 80.32787674737 | 2003 | 79.947758601035 | 2002 | 79.837154364294 | 2001 | 79.74502721701 | 2000 | 79.546476224822 | 1999 | 79.616456829714 | 1998 | 79.687755269896 | 1997 | 79.582076141834 | 1996 | 79.302036549442 | 1995 | 79.109750582657 | 1994 | 79.191486204413 | 1993 | 79.002940919947 | 1992 | 79.293751778678 | 1991 | 79.088562761333 | 1990 | 78.990516481968 | 1989 | 78.695559187869 | 1988 | 78.492269203507 | 1987 | 78.483484530267 | 1986 | 78.361331660524 | 1985 | 78.354116368065 | 1984 | 78.356140981251 | 1983 | 78.24545199431 | 1982 | 78.214451343484 | 1981 | 77.930382578392 | 1980 | 77.53295640498 | 1979 | 77.875070576962 | 1978 | 77.39716884084 | 1977 | 77.273188473262 | 1976 | 76.87492894557 | 1975 | 76.659692102035 | 1974 | 75.995364826559 | 1973 | 75.443763072736 | 1972 | 75.23555616864 | 1971 | 75.151900877969 | 1970 | 74.842837193492 | 1969 | 74.547489396429 | 1968 | 74.253510202205 | 1967 | 74.423688134877 | 1966 | 74.033604964292 | 1965 | 73.920237068013 | 1964 | 73.823261579032 | 1963 | 73.496400901789 | 1962 | 73.581537847759 | 1961 | 73.673865386416 | 1960 | 73.192298815307 |
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