Hurrell PC-Based North Atlantic Oscillation Index (JJA)
  1899    0.22
  1900   -0.65
  1901    1.04
  1902   -2.17
  1903   -2.11
  1904   -1.02
  1905   -0.04
  1906   -0.67
  1907   -1.91
  1908   -0.02
  1909   -0.12
  1910   -1.66
  1911   -0.50
  1912   -1.41
  1913    0.79
  1914    0.41
  1915   -1.55
  1916   -0.37
  1917   -0.46
  1918   -0.55
  1919    1.04
  1920    0.92
  1921    0.23
  1922    0.63
  1923   -0.15
  1924   -0.07
  1925    0.60
  1926   -0.31
  1927   -0.36
  1928   -0.98
  1929   -0.56
  1930   -0.50
  1931   -0.93
  1932   -0.03
  1933    1.02
  1934   -0.39
  1935    0.70
  1936    0.44
  1937    1.31
  1938    1.11
  1939   -0.02
  1940    0.65
  1941    0.73
  1942    0.29
  1943   -1.35
  1944   -0.14
  1945   -0.41
  1946    0.95
  1947    1.07
  1948   -0.70
  1949    0.16
  1950   -0.33
  1951   -0.20
  1952    0.38
  1953    0.75
  1954   -0.28
  1955    1.79
  1956   -0.79
  1957   -0.69
  1958   -2.34
  1959    0.44
  1960   -0.82
  1961    1.45
  1962   -0.58
  1963   -0.74
  1964    0.59
  1965    0.03
  1966    0.11
  1967    1.67
  1968   -0.06
  1969    0.39
  1970    1.14
  1971    0.06
  1972    1.30
  1973    1.08
  1974   -0.16
  1975    0.92
  1976    1.48
  1977   -0.61
  1978    0.18
  1979    1.08
  1980   -0.93
  1981    0.88
  1982   -0.14
  1983    2.12
  1984    1.08
  1985   -0.47
  1986    0.39
  1987   -1.06
  1988    0.69
  1989    1.58
  1990    0.68
  1991    0.72
  1992    0.27
  1993   -1.14
  1994    2.05
  1995    0.72
  1996    1.28
  1997    0.04
  1998   -0.67
  1999    0.94
  2000   -0.05
  2001   -0.04
  2002    0.80
  2003   -0.31
  2004   -0.31
  2005    0.55
  2006    1.09
  2007   -1.13
  2008   -1.34
  2009   -2.07
  2010   -0.44
  2011   -2.12
  2012   -1.60
  2013    1.68
  2014   -0.86
  2015   -1.64
  2016   -0.69
  2017    0.36
  2018    1.89
  2019   -2.10
  2020   -0.31
  2021    1.09
  2022    0.43
  2023   -1.34