"Year","JAN","FEB","MAR","APR","MAY","JUN","JUL","AUG","SEP","OCT","NOV","DEC"
1915,4.1,4.2,4.2,4.2,4.3,4.5,4.5,4.5,4.5,4.7,4.8,4.9
1916,4.9,4.9,5.0,5.0,5.1,5.2,5.3,5.3,5.4,5.5,5.8,6.0
1917,6.0,6.0,6.1,6.2,6.3,6.4,6.5,6.5,6.6,6.4,6.7,6.7
1918,6.8,6.9,6.9,7.0,7.1,7.2,7.3,7.6,7.6,7.9,8.0,7.9
1919,7.9,7.9,7.8,7.6,7.4,7.4,7.5,7.8,7.8,7.9,8.1,8.1
1920,8.1,8.3,8.3,8.4,8.7,9.0,9.1,9.2,9.4,9.5,10.0,9.7
1921,9.6,9.1,8.7,8.4,8.2,7.9,7.9,8.0,7.9,7.6,7.3,7.2
1922,6.9,6.8,6.7,6.6,6.5,6.5,6.6,6.5,6.5,6.4,6.5,6.5
1923,6.4,6.4,6.4,6.3,6.1,6.1,6.1,6.2,6.2,6.3,6.3,6.4
1924,6.4,6.5,6.4,6.2,6.2,6.1,6.1,6.2,6.2,6.4,6.5,6.5
1925,6.5,6.5,6.5,6.3,6.2,6.2,6.2,6.2,6.3,6.4,6.4,6.4
1926,6.3,6.2,6.2,6.1,6.0,6.1,6.1,6.1,6.2,6.3,6.5,6.5
1927,6.3,6.2,6.2,6.0,5.9,5.9,6.0,5.9,6.0,6.0,6.1,6.1
1928,6.1,6.0,5.9,5.9,5.9,6.0,6.0,6.0,6.0,6.0,6.0,6.1
1929,6.0,6.0,6.0,5.9,5.8,5.8,5.8,5.9,5.9,6.0,6.0,6.0
1930,6.0,5.9,5.8,5.7,5.6,5.6,5.6,5.7,5.7,5.6,5.7,5.6
1931,5.5,5.5,5.4,5.3,5.3,5.2,5.3,5.2,5.2,5.2,5.3,5.3
1932,5.3,5.3,5.3,5.2,5.2,5.1,5.2,5.1,5.1,5.2,5.2,5.2
1933,5.1,5.1,5.0,4.9,4.9,4.9,5.0,5.0,5.1,5.1,5.2,5.2
1934,5.1,5.1,5.1,5.0,4.9,5.0,5.1,5.1,5.2,5.2,5.2,5.2
1935,5.2,5.1,5.1,5.0,5.0,5.1,5.2,5.2,5.2,5.2,5.3,5.3
1936,5.3,5.3,5.3,5.2,5.2,5.2,5.3,5.3,5.3,5.3,5.5,5.5
1937,5.5,5.5,5.5,5.5,5.5,5.5,5.6,5.6,5.6,5.7,5.8,5.8
1938,5.7,5.7,5.6,5.6,5.6,5.6,5.7,5.6,5.6,5.6,5.6,5.6
1939,5.6,5.6,5.5,5.5,5.5,5.5,5.6,5.6,5.6,6.0,6.1,6.2
1940,6.3,6.4,6.5,6.4,6.5,6.5,6.8,6.7,6.8,6.8,6.9,7.0
1941,7.1,7.1,7.1,7.2,7.2,7.2,7.2,7.2,7.2,7.2,7.2,7.3
1942,7.2,7.2,7.2,7.2,7.2,7.2,7.2,7.3,7.2,7.2,7.2,7.2
1943,7.2,7.2,7.2,7.2,7.2,7.2,7.2,7.2,7.2,7.2,7.2,7.2
1944,7.2,7.2,7.2,7.2,7.2,7.2,7.3,7.3,7.3,7.3,7.3,7.3
1945,7.3,7.3,7.3,7.3,7.3,7.4,7.5,7.4,7.3,7.3,7.3,7.3
1946,7.3,7.3,7.3,7.3,7.4,7.3,7.4,7.4,7.3,7.3,7.3,7.4
1947,7.4,7.3,7.4,7.3,7.3,7.3,7.4,7.3,7.4,7.4,7.6,7.6
1948,7.6,7.8,7.8,7.9,7.9,8.0,7.9,7.9,7.9,7.9,8.0,8.0
1949,8.0,8.0,8.0,8.0,8.1,8.1,8.2,8.2,8.2,8.2,8.2,8.3
1950,8.3,8.3,8.3,8.3,8.4,8.3,8.3,8.3,8.3,8.4,8.5,8.5
1951,8.6,8.7,8.7,8.9,9.1,9.1,9.3,9.3,9.4,9.4,9.5,9.5
1952,9.7,9.7,9.8,9.9,9.9,10.1,10.1,10.0,10.0,10.1,10.1,10.2
1953,10.1,10.2,10.2,10.3,10.3,10.4,10.4,10.3,10.3,10.3,10.3,10.3
1954,10.3,10.3,10.4,10.4,10.4,10.4,10.6,10.5,10.5,10.6,10.6,10.7
1955,10.7,10.7,10.7,10.8,10.7,11.0,11.0,10.9,11.0,11.1,11.3,11.3
1956,11.2,11.2,11.4,11.6,11.5,11.5,11.5,11.5,11.5,11.6,11.6,11.6
1957,11.7,11.7,11.7,11.8,11.8,11.9,12.0,12.0,11.9,12.0,12.1,12.2
1958,12.2,12.1,12.2,12.3,12.3,12.4,12.2,12.2,12.2,12.3,12.4,12.4
1959,12.4,12.4,12.4,12.3,12.3,12.3,12.3,12.3,12.2,12.3,12.4,12.4
1960,12.36,12.36,12.34,12.41,12.41,12.47,12.50,12.42,12.43,12.53,12.59,12.62
1961,12.63,12.63,12.68,12.74,12.78,12.89,12.89,13.01,12.99,13.01,13.15,13.17
1962,13.22,13.23,13.28,13.47,13.51,13.60,13.55,13.43,13.41,13.40,13.45,13.52
1963,13.57,13.69,13.71,13.74,13.73,13.73,13.65,13.61,13.65,13.71,13.74,13.77
1964,13.84,13.85,13.90,14.02,14.14,14.19,14.19,14.25,14.25,14.26,14.38,14.43
1965,14.47,14.47,14.52,14.80,14.85,14.89,14.89,14.92,14.93,14.95,15.01,15.08
1966,15.11,15.12,15.15,15.33,15.44,15.48,15.41,15.50,15.48,15.52,15.61,15.63
1967,15.66,15.67,15.67,15.79,15.78,15.85,15.75,15.71,15.70,15.82,15.91,16.02
1968,16.07,16.15,16.20,16.49,16.51,16.57,16.59,16.61,16.63,16.71,16.74,16.97
1969,17.06,17.15,17.22,17.41,17.38,17.46,17.46,17.42,17.47,17.60,17.64,17.76
1970,17.91,18.00,18.11,18.38,18.44,18.49,18.62,18.61,18.70,18.90,19.03,19.16
1971,19.43,19.53,19.69,20.11,20.25,20.39,20.51,20.52,20.55,20.67,20.79,20.89
1972,21.01,21.12,21.19,21.38,21.49,21.63,21.70,21.87,21.99,22.30,22.37,22.49
1973,22.64,22.78,22.92,23.35,23.52,23.64,23.75,23.82,24.03,24.50,24.69,24.87
1974,25.35,25.78,26.01,26.89,27.27,27.55,27.81,27.83,28.14,28.69,29.20,29.63
1975,30.39,30.90,31.51,32.72,34.09,34.75,35.11,35.31,35.61,36.12,36.55,37.01
1976,37.49,37.97,38.17,38.91,39.34,39.54,39.62,40.18,40.71,41.44,42.03,42.59
1977,43.70,44.13,44.56,45.70,46.06,46.54,46.59,46.82,47.07,47.27,47.50,47.76
1978,48.04,48.31,48.62,49.33,49.61,49.99,50.22,50.54,50.75,50.98,51.33,51.76
1979,52.52,52.95,53.38,54.30,54.73,55.67,58.07,58.53,59.11,59.72,60.25,60.68
1980,62.18,63.07,63.93,66.11,66.72,67.35,67.91,68.06,68.49,68.92,69.48,69.86
1981,70.29,70.93,71.99,74.07,74.55,74.98,75.31,75.87,76.30,76.98,77.79,78.28
1982,78.73,78.76,79.44,81.04,81.62,81.85,81.88,81.90,81.85,82.26,82.66,82.51
1983,82.61,82.97,83.12,84.28,84.64,84.84,85.30,85.68,86.06,86.36,86.67,86.89
1984,86.84,87.20,87.48,88.64,88.97,89.20,89.10,89.94,90.11,90.67,90.95,90.87
1985,91.20,91.94,92.80,94.78,95.21,95.41,95.23,95.49,95.44,95.59,95.92,96.05
1986,96.25,96.60,96.73,97.67,97.85,97.79,97.52,97.82,98.30,98.45,99.29,99.62
1987,100.0,100.4,100.6,101.8,101.9,101.9,101.8,102.1,102.4,102.9,103.4,103.3
1988,103.3,103.7,104.1,105.8,106.2,106.6,106.7,107.9,108.4,109.5,110.0,110.3
1989,111.0,111.8,112.3,114.3,115.0,115.4,115.5,115.8,116.6,117.5,118.5,118.8
1990,119.5,120.2,121.4,125.1,126.2,126.7,126.8,128.1,129.3,130.3,130.0,129.9
1991,130.2,130.9,131.4,133.1,133.5,134.1,133.8,134.1,134.6,135.1,135.6,135.7
1992,135.6,136.3,136.7,138.8,139.3,139.3,138.8,138.9,139.4,139.9,139.7,139.2
1993,137.9,138.8,139.3,140.6,141.1,141.0,140.7,141.3,141.9,141.8,141.6,141.9
1994,141.3,142.1,142.5,144.2,144.7,144.7,144.0,144.7,145.0,145.2,145.3,146.0
1995,146.0,146.9,147.5,149.0,149.6,149.8,149.1,149.9,150.6,149.8,149.8,150.7
1996,150.2,150.9,151.5,152.6,152.9,153.0,152.4,153.1,153.8,153.8,153.9,154.4
1997,154.4,155.0,155.4,156.3,156.9,157.5,157.5,158.5,159.3,159.5,159.6,160.0
1998,159.5,160.3,160.8,162.6,163.5,163.4,163.0,163.7,164.4,164.5,164.4,164.4
1999,163.4,163.7,164.1,165.2,165.6,165.6,165.1,165.5,166.2,166.5,166.7,167.3
2000,166.6,167.5,168.4,170.1,170.7,171.1,170.5,170.5,171.7,171.6,172.1,172.2
2001,171.1,172.0,172.2,173.1,174.2,174.4,173.3,174.0,174.6,174.3,173.6,173.4
2002,173.3,173.8,174.5,175.7,176.2,176.2,175.9,176.4,177.6,177.9,178.2,178.5
2003,178.4,179.3,179.9,181.2,181.5,181.3,181.3,181.6,182.5,182.6,182.7,183.5
2004,183.1,183.8,184.6,185.7,186.5,186.8,186.8,187.4,188.1,188.6,189.0,189.9
2005,188.9,189.6,190.5,191.6,192.0,192.2,192.2,192.6,193.1,193.3,193.6,194.1
2006,193.4,194.2,195.0,196.5,197.7,198.5,198.5,199.2,200.1,200.4,201.1,202.7
2007,201.6,203.1,204.4,205.4,206.2,207.3,206.1,207.3,208.0,208.9,209.7,210.9
2008,209.8,211.4,212.1,214.0,215.1,,,,,,,