year PDO 12-yr low-pass filtered PDO 1854 -0.02146 -999.0 1855 -0.44658 -999.0 1856 -0.16719 -999.0 1857 0.99884 -999.0 1858 1.63013 -999.0 1859 -0.89839 -999.0 1860 0.02278 0.14379 1861 -0.10698 0.08520 1862 0.23823 0.05714 1863 0.19615 0.05820 1864 0.03617 0.09260 1865 -0.10487 0.17978 1866 -0.10071 0.33455 1867 0.30144 0.53293 1868 0.35635 0.70427 1869 3.12848 0.76599 1870 0.59426 0.67451 1871 0.35492 0.45442 1872 -0.32727 0.17932 1873 -0.51120 -0.06989 1874 0.25439 -0.24328 1875 -0.52887 -0.33762 1876 -1.29126 -0.38762 1877 -0.20575 -0.44870 1878 0.83510 -0.56394 1879 -0.43375 -0.73244 1880 -2.28067 -0.90021 1881 -0.80689 -0.98669 1882 -1.86937 -0.93528 1883 -1.52979 -0.74271 1884 1.00955 -0.45793 1885 -0.44564 -0.15332 1886 -0.39581 0.10411 1887 0.56701 0.25994 1888 1.71710 0.27795 1889 0.60272 0.14796 1890 -1.37502 -0.09840 1891 1.00924 -0.38675 1892 -1.67238 -0.62196 1893 -1.07587 -0.72247 1894 -2.05198 -0.65842 1895 0.13966 -0.46339 1896 -0.14364 -0.21307 1897 0.71671 0.02133 1898 0.35340 0.20722 1899 -0.40988 0.35558 1900 1.12288 0.49629 1901 -0.51974 0.64449 1902 2.16358 0.78919 1903 0.74553 0.89659 1904 0.41449 0.92832 1905 1.79584 0.85597 1906 1.25193 0.67467 1907 0.20548 0.42012 1908 0.30632 0.16196 1909 -1.21887 -0.02097 1910 -0.23185 -0.08062 1911 -0.45381 -0.03090 1912 0.50001 0.06236 1913 0.97677 0.11597 1914 -0.55604 0.07497 1915 1.44956 -0.06491 1916 -1.29474 -0.26914 1917 -0.74303 -0.48431 1918 -0.27843 -0.66325 1919 -1.03859 -0.77460 1920 -1.17671 -0.80100 1921 -1.24176 -0.73856 1922 -0.50176 -0.59550 1923 -0.08070 -0.39495 1924 -0.51841 -0.17440 1925 -0.54780 0.02498 1926 1.85209 0.17381 1927 0.01567 0.26300 1928 -0.12303 0.29964 1929 0.27697 0.29033 1930 -0.00200 0.23997 1931 1.72347 0.16868 1932 0.03415 0.11834 1933 -2.24027 0.13527 1934 0.43232 0.22926 1935 0.74139 0.36180 1936 2.08891 0.48455 1937 0.30756 0.58393 1938 -0.31266 0.68452 1939 -0.55729 0.79749 1940 1.86190 0.88016 1941 3.09920 0.86091 1942 1.02040 0.70944 1943 -0.57906 0.47641 1944 -1.13101 0.25108 1945 0.57836 0.08166 1946 0.19164 -0.06084 1947 0.72530 -0.23943 1948 -0.22478 -0.47544 1949 -1.21734 -0.71836 1950 -2.25149 -0.88640 1951 -0.74716 -0.93405 1952 -1.38259 -0.87958 1953 0.09239 -0.77188 1954 0.20525 -0.64160 1955 -2.05216 -0.48529 1956 -1.10133 -0.29608 1957 0.84023 -0.10372 1958 0.98637 0.02620 1959 0.06905 0.03495 1960 0.41975 -0.08140 1961 -0.45797 -0.26410 1962 -1.06732 -0.42700 1963 -0.82704 -0.50460 1964 -0.76972 -0.48113 1965 -0.23346 -0.38621 1966 0.20654 -0.27395 1967 -0.79949 -0.19995 1968 0.49061 -0.20147 1969 0.33451 -0.28408 1970 -0.50793 -0.41651 1971 -1.13033 -0.54275 1972 -0.98376 -0.60900 1973 -0.90697 -0.58818 1974 0.04987 -0.48939 1975 -0.95228 -0.34507 1976 0.02634 -0.18791 1977 0.45706 -0.03622 1978 -0.42759 0.10981 1979 0.47260 0.25591 1980 0.00960 0.40049 1981 1.23733 0.53178 1982 -0.04838 0.63382 1983 1.81409 0.69877 1984 0.31947 0.72850 1985 0.37364 0.72651 1986 0.76709 0.68848 1987 1.46404 0.60879 1988 0.36639 0.49950 1989 0.28886 0.39891 1990 -0.03997 0.35410 1991 -0.83821 0.38923 1992 1.09040 0.48970 1993 1.85482 0.60787 1994 -0.26970 0.68750 1995 0.91200 0.68170 1996 0.62396 0.56259 1997 2.07551 0.33712 1998 -0.37893 0.05677 1999 -1.34563 -0.18936 2000 -0.77728 -0.31602 2001 -0.84996 -0.28987 2002 -0.00417 -0.14713 2003 0.64359 0.02703 2004 0.20151 0.14724 2005 0.51394 0.16259 2006 0.17248 0.06363 2007 0.55431 -0.12911 2008 -1.15980 -0.37689 2009 -0.14340 -0.62307 2010 -1.08750 -0.79778 2011 -1.48782 -0.83407 2012 -1.60674 -0.69997 2013 -0.88419 -999.0 2014 0.42063 -999.0 2015 1.23130 -999.0 2016 0.68743 -999.0 2017 0.33666 -999.0 2018 -0.04275 -999.0