year PDO 12-yr low-pass filtered PDO 1855 -0.05996 -999.0 1856 0.67738 -999.0 1857 -0.50830 -999.0 1858 -0.43186 -999.0 1859 -0.79198 -999.0 1860 -0.76882 -999.0 1861 -0.63141 -0.38181 1862 -0.40366 -0.24625 1863 0.29288 -0.10304 1864 0.29489 0.00858 1865 0.59067 0.07720 1866 -0.84365 0.11469 1867 0.24568 0.13622 1868 0.68327 0.14070 1869 0.04320 0.11092 1870 0.16923 0.03041 1871 0.11927 -0.09681 1872 -0.07340 -0.23668 1873 -1.01931 -0.33417 1874 -0.49811 -0.33721 1875 -0.85405 -0.22527 1876 -0.04799 -0.02655 1877 0.24275 0.18644 1878 1.10789 0.32615 1879 1.08407 0.33384 1880 0.10919 0.21687 1881 0.31131 0.04747 1882 -0.96790 -0.07996 1883 -0.50826 -0.10704 1884 -1.40366 -0.04527 1885 2.18147 0.04221 1886 0.71416 0.08989 1887 -0.88599 0.07267 1888 -0.51027 0.00374 1889 0.72856 -0.09731 1890 -0.12826 -0.22303 1891 -0.38566 -0.36813 1892 -0.49022 -0.50549 1893 -0.65220 -0.58495 1894 -1.75318 -0.56058 1895 -0.70708 -0.42295 1896 0.14835 -0.20739 1897 0.76474 0.03186 1898 0.00795 0.25214 1899 -0.16232 0.43786 1900 1.18291 0.59663 1901 1.01543 0.74179 1902 0.59338 0.87923 1903 0.83024 0.99744 1904 0.54794 1.06755 1905 3.09170 1.05546 1906 0.90309 0.93865 1907 -0.53328 0.72542 1908 1.58023 0.45781 1909 0.65531 0.19845 1910 -1.64385 0.00772 1911 -0.26395 -0.08843 1912 0.10144 -0.11510 1913 0.01605 -0.13189 1914 0.29903 -0.19151 1915 0.40275 -0.30039 1916 -0.90354 -0.41710 1917 -2.09056 -0.48941 1918 -0.22817 -0.49688 1919 0.71033 -0.46362 1920 -0.57878 -0.42718 1921 -0.86866 -0.39963 1922 -0.47576 -0.35935 1923 -0.22781 -0.27193 1924 -0.17208 -0.12169 1925 -0.93919 0.07494 1926 1.20057 0.27816 1927 1.05680 0.44193 1928 0.25847 0.52935 1929 0.28247 0.51873 1930 1.17558 0.41408 1931 1.09853 0.25524 1932 -0.85419 0.11247 1933 -0.74940 0.05658 1934 -0.62403 0.11772 1935 0.69246 0.27424 1936 1.40422 0.47894 1937 0.30412 0.69600 1938 0.74834 0.90933 1939 0.18025 1.09522 1940 1.86776 1.19927 1941 2.88532 1.15471 1942 2.09586 0.93378 1943 -1.31488 0.57878 1944 0.64704 0.17664 1945 -0.42116 -0.19870 1946 -0.96233 -0.52046 1947 -0.40431 -0.79600 1948 -0.23326 -1.02773 1949 -2.68215 -1.19058 1950 -1.65898 -1.24975 1951 -0.99830 -1.20042 1952 -1.52947 -1.08248 1953 -0.35770 -0.95373 1954 -0.51101 -0.84378 1955 -0.27412 -0.72876 1956 -2.00433 -0.55872 1957 -1.33232 -0.31331 1958 0.92072 -0.03836 1959 1.20615 0.17425 1960 0.70353 0.25134 1961 0.78545 0.18575 1962 -1.24005 0.03329 1963 0.01363 -0.13077 1964 0.16587 -0.25555 1965 -0.94563 -0.32387 1966 -0.17894 -0.34262 1967 -0.34558 -0.33237 1968 -0.78376 -0.32313 1969 -0.14627 -0.34782 1970 1.20937 -0.42406 1971 -1.31916 -0.53856 1972 -1.90310 -0.64466 1973 0.24842 -0.68597 1974 -1.19321 -0.62484 1975 -0.66048 -0.45793 1976 -1.37734 -0.21799 1977 1.39781 0.04467 1978 0.85745 0.28374 1979 -0.47228 0.47556 1980 0.96611 0.61999 1981 1.18337 0.72677 1982 0.30088 0.80721 1983 1.16575 0.86535 1984 1.30256 0.89403 1985 0.36704 0.87441 1986 0.90338 0.78049 1987 1.56804 0.59895 1988 1.01391 0.35301 1989 -1.10323 0.10851 1990 -0.34504 -0.05581 1991 -1.11333 -0.09608 1992 0.39288 -0.02478 1993 0.43705 0.10674 1994 0.80704 0.24214 1995 -0.59383 0.34093 1996 0.68210 0.37533 1997 0.50463 0.32899 1998 1.91552 0.21264 1999 -0.75765 0.07456 2000 -1.46844 -0.01508 2001 0.08565 -0.01293 2002 -0.43775 0.06200 2003 1.82204 0.13864 2004 -0.06453 0.14045 2005 -0.06075 0.03737 2006 0.22694 -0.14646 2007 -0.14160 -0.35917 2008 -1.37932 -0.55725 2009 -1.32307 -0.71860 2010 0.65135 -0.82428 2011 -1.44737 -0.84163 2012 -1.85399 -0.72950 2013 -1.09351 -999.0 2014 -0.65883 -999.0 2015 1.82124 -999.0 2016 1.28257 -999.0 2017 0.36867 -999.0 2018 0.11150 -999.0