Hurrell PC-Based North Atlantic Oscillation Index (SON)
  1899     1.25
  1900     0.35
  1901    -0.72
  1902    -0.83
  1903    -0.17
  1904    -0.43
  1905    -0.54
  1906    -0.59
  1907    -0.17
  1908    -0.53
  1909    -0.74
  1910    -2.07
  1911     0.17
  1912    -0.38
  1913     0.61
  1914    -0.14
  1915    -2.87
  1916     0.39
  1917     1.74
  1918     0.58
  1919    -1.28
  1920    -0.39
  1921    -0.97
  1922    -1.29
  1923     1.83
  1924     0.51
  1925    -0.45
  1926    -0.12
  1927    -0.48
  1928     0.55
  1929     1.57
  1930     0.27
  1931    -0.13
  1932     1.19
  1933    -1.43
  1934     0.44
  1935     1.46
  1936     0.66
  1937    -0.40
  1938     2.18
  1939    -1.08
  1940     0.58
  1941    -1.58
  1942     0.41
  1943     0.03
  1944     0.36
  1945    -1.40
  1946    -0.51
  1947    -0.52
  1948     1.04
  1949    -0.23
  1950     1.03
  1951    -0.08
  1952    -1.15
  1953     1.55
  1954     1.99
  1955    -0.99
  1956     0.54
  1957     0.38
  1958    -0.31
  1959    -0.34
  1960    -1.29
  1961     0.69
  1962    -0.21
  1963     1.07
  1964     0.07
  1965    -1.12
  1966    -0.63
  1967     1.87
  1968    -2.72
  1969     1.67
  1970     0.30
  1971     0.02
  1972    -0.10
  1973    -0.96
  1974     0.26
  1975     0.44
  1976    -0.91
  1977     1.22
  1978     2.01
  1979     0.39
  1980    -0.90
  1981    -0.38
  1982     1.92
  1983     0.48
  1984     0.53
  1985    -0.66
  1986     2.21
  1987    -0.04
  1988    -0.33
  1989     0.58
  1990    -0.12
  1991     0.63
  1992     0.52
  1993    -1.41
  1994    -0.41
  1995    -1.14
  1996     0.00
  1997    -1.03
  1998    -1.09
  1999     0.54
  2000     0.64
  2001     0.62
  2002    -1.95
  2003    -0.11
  2004     0.01
  2005    -0.04
  2006    -0.08
  2007    -0.22
  2008     1.14
  2009     0.48
  2010    -1.55
  2011     1.77
  2012     0.25
  2013     0.40
  2014    -0.82
  2015     0.47
  2016    -0.98
  2017     0.06
  2018    -0.22
  2019    -0.88
  2020     1.30
  2021    -0.77
  2022     0.09