Year | Value | 2021 | 392 | 2020 | 398 | 2019 | 403 | 2018 | 403 | 2017 | 402 | 2016 | 407 | 2015 | 404 | 2014 | 389 | 2013 | 388 | 2012 | 384 | 2011 | 426.1 | 2010 | 433.8 | 2009 | 434.2 | 2008 | 442.8 | 2007 | 421.2 | 2006 | 423.6 | 2005 | 461.1 | 2004 | 458 | 2003 | 457.7 | 2002 | 454 | 2001 | 442 | 2000 | 438 | 1999 | 434 | 1998 | 430 | 1997 | 425 | 1996 | 421 | 1995 | 417 | 1994 | 413 | 1993 | 408 | 1992 | 404 | 1991 | 400 | 1990 | 396 | 1989 | 391 | 1988 | 387 | 1987 | 383 | 1986 | 379 | 1985 | 374 | 1984 | 370 | 1983 | 366 | 1982 | 363 | 1981 | 358 | 1980 | 354 | 1979 | 349 | 1978 | 345 | 1977 | 341 | 1976 | 337 | 1975 | 332 | 1974 | 328 | 1973 | 324 | 1972 | 320 | 1971 | 316 | 1970 | 316 | 1969 | 316 | 1968 | 312 | 1967 | 311 | 1966 | 310 | 1965 | 320 | 1964 | 318 | 1963 | 322 | 1962 | 325 | 1961 | 325 |
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