DJF MAM JJA SON 1905 986.582 985.622 983.288 985.625 1906 984.767 987.368 990.087 983.313 1907 982.791 985.212 991.049 984.197 1908 987.99 984.629 983.656 982.366 1909 990.084 987.425 986.186 983.143 1910 987.521 985.766 988.705 983.478 1911 993.051 987.067 983.293 982.757 1912 989.237 986.203 983.102 984.815 1913 987.846 987.895 989.37 984.496 1914 988.625 985.264 987.149 982.085 1915 986.569 988.696 987.465 984.978 1916 987.163 988.39 982.635 985.46 1917 986.168 985.44 989.112 980.909 1918 985.753 987.094 981.823 985.087 1919 986.568 984.639 983.095 985.667 1920 987.826 984.855 988.622 984.122 1921 989.542 987.716 987.841 980.791 1922 989.84 986.438 984.681 983.273 1923 987.321 989.314 987.687 984.725 1924 990.282 985.24 984.511 981.17 1925 992.343 986.41 985.049 985.074 1926 987.809 987.101 986.565 986.982 1927 983.879 988.385 986.373 983.632 1928 989.769 985.362 987.65 985.054 1929 989.905 986.738 983.992 984.61 1930 988.249 983.661 987.678 984.206 1931 989.982 985.508 985.909 982.645 1932 992.084 986.086 985.663 983.587 1933 987.346 985.492 986.219 982.309 1934 987.548 985.022 983.746 981.757 1935 988.243 988.142 986.3 984.387 1936 991.278 987.624 983.71 983.586 1937 988.754 987.418 985.739 981.775 1938 992.358 987.932 983.107 982.627 1939 990.184 987.213 986.332 984.673 1940 985.105 987.675 988.112 982.084 1941 990.38 987.32 986.134 985.333 1942 987.692 985.213 989.322 984.09 1943 985.489 985.581 988.189 983.554 1944 988.537 985.268 984.885 986.334 1945 990.483 986.962 988.965 984.822 1946 989.606 987.353 987.764 988.523 1947 985.843 984.562 989.43 982.161 1948 990.285 986.733 987.783 985.562 1949 990.936 985.742 989.053 982.944 1950 987.935 987.278 986.409 982.284 1951 990.943 989.94 985.832 986.008 1952 989.382 989.961 986.869 984.437 1953 988.831 988.909 984.604 987.584 1954 989.449 988.566 988.465 983.553 1955 988.962 988.861 987.502 983.957 1956 990.652 992.242 989.013 984.17 1957 991.411 988.492 989.239 985.951 1958 987.323 990.997 987.792 985.19 1959 989.612 989.195 990.134 984.067 1960 989.387 987.793 986.787 984.167 1961 985.938 987.874 988.361 984.8 1962 985.297 986.765 991.319 984.99 1963 990.042 986.88 992.463 983.276 1964 992.941 986.616 996.103 983.851 1965 988.857 987.642 989.375 985.909 1966 990.392 987.303 987.042 981.731 1967 990.684 985.637 986.083 984.74 1968 991.749 988.674 988.995 987.037 1969 987.673 988.272 985.656 985.42 1970 990.072 989.905 986.85 985.089 1971 991.414 989.283 988.328 985.744 1972 989.319 989.9 989.46 985.258 1973 986.009 987.733 986.039 983.04 1974 991.211 987.451 991.443 982.609 1975 989.473 989.927 988.53 983.756 1976 991.98 986.306 986.156 984.094 1977 986.477 990.308 989.986 984.49 1978 988.698 989.206 987.161 984.728 1979 991.717 987.193 984.608 984.367 1980 988.409 990.616 985.09 984.343 1981 987.949 988.375 988.773 983.42 1982 991.519 985.552 984.107 985.545 1983 990.367 989.72 987.67 982.782 1984 991.226 988.333 985.996 983.981 1985 990.523 989.742 985.617 981.967 1986 989.781 990.712 985.876 982.072 1987 988.39 988.229 985.17 983.482 1988 987.662 986.579 990.741 984.575 1989 986.956 986.08 983.861 982.22 1990 989.412 990.802 985.477 983.88 1991 989.134 989.069 989.312 984.879 1992 989.51 989.553 989.108 982.816 1993 987.519 986.838 981.934 982.5 1994 984.897 987.827 988.274 984.687 1995 988.464 986.188 989.445 982.917 1996 987.931 985.495 990.723 984.894 1997 986.743 984.912 983.251 984.291 1998 984.811 983.951 984.363 981.951 1999 985.815 984.198 985.161 980.204 2000 992.449 984.894 985.789 982.843 2001 987.775 986.47 984.729 981.846 2002 988.089 990.44 985.805 986.474 2003 989.001 986.31 986.159 986.003 2004 989.487 984.408 984.022 984.338 2005 989.363 986.177 987.468 981.679 2006 986.235 985.747 987.277 984.7 2007 984.008 987.42 991.899 985.986 2008 986.279 989.588 984.827 982.42 2009 990.129 987.365 987.138 986.915 2010 987.14 985.634 980.082 982.786 2011 985.102 992.458 983.478