Hurrell PC-Based North Atlantic Oscillation Index (Annual)
  1899   -0.59
  1900   -0.37
  1901   -0.65
  1902   -1.25
  1903    0.57
  1904    0.72
  1905    0.78
  1906    0.23
  1907    0.41
  1908    0.68
  1909   -1.09
  1910   -0.20
  1911    0.97
  1912    0.30
  1913    1.81
  1914    1.48
  1915   -2.14
  1916   -0.37
  1917   -0.69
  1918    0.31
  1919   -0.33
  1920    1.31
  1921    1.41
  1922    0.73
  1923    0.74
  1924   -0.04
  1925    0.25
  1926   -0.22
  1927   -0.04
  1928    1.00
  1929    0.22
  1930    0.19
  1931   -0.61
  1932   -0.18
  1933   -0.45
  1934    0.76
  1935    0.08
  1936   -0.35
  1937   -0.38
  1938    1.73
  1939   -0.36
  1940   -1.30
  1941   -1.09
  1942   -0.70
  1943    1.06
  1944    0.11
  1945   -0.96
  1946    0.60
  1947   -1.15
  1948    0.74
  1949    0.95
  1950    0.15
  1951   -0.36
  1952   -1.45
  1953    0.86
  1954    0.67
  1955   -1.84
  1956   -0.08
  1957   -0.24
  1958   -1.92
  1959    0.50
  1960   -1.89
  1961    0.33
  1962   -0.56
  1963   -1.11
  1964    0.01
  1965   -1.07
  1966   -1.85
  1967    1.15
  1968   -1.71
  1969   -1.83
  1970   -0.87
  1971   -0.38
  1972    0.97
  1973    0.21
  1974    0.69
  1975    0.55
  1976    0.72
  1977   -0.75
  1978   -0.28
  1979   -0.36
  1980   -1.07
  1981   -0.89
  1982    1.47
  1983    0.45
  1984    0.82
  1985   -1.27
  1986    1.32
  1987   -1.17
  1988    0.13
  1989    2.24
  1990    2.51
  1991    0.97
  1992    1.66
  1993    0.67
  1994    1.34
  1995   -0.83
  1996   -1.07
  1997    0.03
  1998   -0.29
  1999    0.57
  2000    0.65
  2001   -0.58
  2002    0.35
  2003    0.33
  2004    0.10
  2005   -0.74
  2006   -0.24
  2007    0.55
  2008    0.10
  2009   -0.75
  2010   -3.64
  2011    1.13
  2012   -0.53
  2013   -0.17
  2014    0.55
  2015    1.92
  2016    0.40
  2017    0.35
  2018    0.76
  2019   -0.68
  2020    1.50
  2021   -1.13
  2022    0.18
  2023   -1.09
  2024   -0.32
  2025    0.54