Hurrell PC-Based North Atlantic Oscillation Index (SON)
  1899    1.26
  1900    0.37
  1901   -0.71
  1902   -0.80
  1903   -0.18
  1904   -0.38
  1905   -0.55
  1906   -0.56
  1907   -0.11
  1908   -0.49
  1909   -0.74
  1910   -2.06
  1911    0.18
  1912   -0.35
  1913    0.62
  1914   -0.10
  1915   -2.86
  1916    0.39
  1917    1.75
  1918    0.59
  1919   -1.26
  1920   -0.33
  1921   -0.91
  1922   -1.27
  1923    1.80
  1924    0.53
  1925   -0.48
  1926   -0.14
  1927   -0.49
  1928    0.55
  1929    1.57
  1930    0.24
  1931   -0.10
  1932    1.18
  1933   -1.40
  1934    0.45
  1935    1.44
  1936    0.69
  1937   -0.39
  1938    2.19
  1939   -1.07
  1940    0.57
  1941   -1.53
  1942    0.43
  1943    0.05
  1944    0.38
  1945   -1.37
  1946   -0.51
  1947   -0.51
  1948    1.05
  1949   -0.21
  1950    1.00
  1951   -0.08
  1952   -1.17
  1953    1.61
  1954    1.99
  1955   -1.00
  1956    0.58
  1957    0.39
  1958   -0.25
  1959   -0.30
  1960   -1.32
  1961    0.69
  1962   -0.19
  1963    1.06
  1964    0.09
  1965   -1.12
  1966   -0.64
  1967    1.88
  1968   -2.75
  1969    1.67
  1970    0.28
  1971    0.05
  1972   -0.07
  1973   -0.95
  1974    0.26
  1975    0.49
  1976   -0.90
  1977    1.22
  1978    2.07
  1979    0.40
  1980   -0.92
  1981   -0.40
  1982    1.93
  1983    0.46
  1984    0.51
  1985   -0.64
  1986    2.26
  1987   -0.01
  1988   -0.31
  1989    0.61
  1990   -0.13
  1991    0.63
  1992    0.51
  1993   -1.34
  1994   -0.42
  1995   -1.17
  1996   -0.02
  1997   -1.07
  1998   -1.12
  1999    0.55
  2000    0.61
  2001    0.63
  2002   -1.99
  2003   -0.10
  2004   -0.01
  2005   -0.04
  2006   -0.15
  2007   -0.18
  2008    1.15
  2009    0.45
  2010   -1.61
  2011    1.77
  2012    0.20
  2013    0.39
  2014   -0.81
  2015    0.49
  2016   -0.93
  2017    0.05
  2018   -0.20
  2019   -0.93
  2020    1.33
  2021   -0.79
  2022    0.06
  2023   -0.69