| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1963 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 56.11 | c | 56.11 | |
| 1964 | 52.42 | 57.30 | b | 53.75 | g | ----- | z | ----- | z | ----- | z | ----- | z | 68.35 | 67.73 | 64.61 | 55.57 | 51.81 | 59.68 | |||||||
| 1965 | 51.52 | 53.71 | 58.74 | 56.87 | 59.29 | 63.73 | 67.35 | 70.29 | 69.48 | a | 66.29 | 59.47 | 52.32 | 60.76 | ||||||||||||
| 1966 | 52.83 | b | 52.54 | b | 53.87 | 59.57 | 61.68 | 66.63 | 67.29 | 69.16 | 68.73 | 63.77 | 57.90 | 55.23 | 60.77 | |||||||||||
| 1967 | 52.45 | 56.15 | a | ----- | z | 52.64 | p | 63.46 | e | 66.82 | b | 70.29 | 71.17 | b | 69.67 | 63.57 | a | 59.90 | 51.77 | 62.53 | ||||||
| 1968 | 52.80 | a | 57.17 | 57.23 | 57.10 | 60.87 | a | 67.70 | 68.93 | b | 67.28 | b | ----- | z | 61.67 | d | 57.10 | a | 51.38 | b | 59.93 | |||||
| 1969 | 47.47 | a | 52.29 | k | 56.70 | a | 55.33 | 61.71 | 64.50 | 67.90 | 69.84 | 67.75 | b | 64.60 | f | 59.77 | 56.23 | 60.72 | ||||||||
| 1970 | 55.60 | a | 58.93 | 58.16 | 55.77 | 64.13 | 66.57 | 69.77 | 68.45 | 68.27 | 61.16 | 58.50 | 52.39 | 61.47 | ||||||||||||
| 1971 | 51.52 | 53.57 | 50.10 | 56.00 | a | 59.19 | 61.76 | a | 65.65 | 70.10 | a | 69.52 | a | 61.77 | 55.43 | 49.81 | 58.70 | |||||||||
| 1972 | 50.65 | 53.25 | a | 57.42 | 56.38 | a | 61.28 | f | 65.90 | a | 67.76 | b | 69.16 | 67.10 | 64.26 | 57.50 | 49.48 | 59.90 | ||||||||
| 1973 | 51.84 | 58.11 | 53.42 | 59.40 | 62.30 | a | 65.45 | a | 67.61 | 67.39 | 66.83 | a | 62.45 | 53.47 | 54.19 | 60.20 | ||||||||||
| 1974 | 50.81 | 52.50 | 54.39 | c | 57.75 | b | 60.54 | e | 63.50 | b | 66.83 | a | 69.13 | 68.25 | b | 66.29 | g | 56.30 | c | 54.11 | d | 59.46 | ||||
| 1975 | 52.88 | g | 53.04 | b | 53.77 | 54.43 | 62.17 | a | 65.30 | 69.03 | a | 66.52 | 66.41 | a | 60.43 | a | 55.00 | 53.59 | d | 59.97 | ||||||
| 1976 | 53.10 | b | 52.40 | d | 53.13 | 55.83 | f | 64.12 | o | 64.85 | c | 68.57 | h | 68.40 | f | 69.50 | h | 66.74 | l | 61.73 | h | 56.85 | k | 55.87 | ||
| 1977 | 57.48 | f | 58.96 | d | 53.52 | f | 57.19 | i | 59.30 | h | 65.95 | k | 68.36 | q | 68.44 | o | ----- | z | ----- | z | 55.40 | 56.26 | 56.87 | |||
| 1978 | 56.97 | 55.36 | 60.03 | 57.93 | 62.35 | 67.33 | 68.13 | 68.52 | 67.67 | 66.32 | 55.40 | 50.55 | 61.38 | |||||||||||||
| 1979 | 52.45 | 51.71 | 56.97 | 59.30 | 64.19 | 66.80 | 70.32 | 70.32 | 73.03 | 65.45 | 59.63 | 57.77 | 62.33 | |||||||||||||
| 1980 | 53.71 | 57.69 | 56.45 | 59.63 | 61.19 | 63.10 | 68.07 | a | 68.87 | 68.30 | 65.97 | 59.17 | 58.03 | 61.68 | ||||||||||||
| 1981 | 60.68 | 58.57 | 57.65 | 60.10 | 61.32 | 66.60 | 69.45 | 69.03 | 70.03 | 63.37 | a | 58.97 | 54.71 | 62.54 | ||||||||||||
| 1982 | 51.55 | 53.50 | 54.87 | 57.73 | 62.68 | 63.10 | 67.48 | 69.35 | 69.03 | 65.90 | 57.73 | 55.13 | 60.67 | |||||||||||||
| 1983 | 57.32 | 61.50 | z | 58.23 | 59.10 | 60.00 | b | 65.63 | 68.68 | 70.94 | 70.37 | 64.90 | 58.03 | 53.73 | a | 62.45 | ||||||||||
| 1984 | 57.77 | 56.21 | 59.45 | 57.23 | 61.48 | 63.17 | 67.61 | 71.16 | 70.37 | 61.58 | 57.37 | 53.32 | 61.39 | |||||||||||||
| 1985 | 56.84 | 54.54 | 53.39 | 59.33 | 61.77 | 66.67 | 68.48 | 68.16 | 66.80 | 62.90 | 53.33 | 55.10 | 60.61 | |||||||||||||
| 1986 | 57.03 | 57.21 | 59.87 | 57.60 | 61.74 | 66.30 | 68.06 | 67.84 | 66.17 | 61.90 | 59.37 | 57.26 | 61.70 | |||||||||||||
| 1987 | 54.74 | 57.64 | 58.58 | 61.40 | 64.90 | b | 66.14 | b | 65.87 | 70.29 | 68.00 | 67.16 | 58.30 | 53.61 | 62.22 | |||||||||||
| 1988 | 53.48 | 55.97 | 56.48 | 59.10 | 59.87 | 65.03 | 69.23 | 67.87 | 68.37 | 64.35 | 55.77 | 54.74 | 60.86 | |||||||||||||
| 1989 | 51.97 | 49.82 | 53.00 | 61.90 | 61.48 | 65.77 | 67.77 | 70.00 | 67.57 | 63.68 | 59.40 | 55.68 | 60.67 | |||||||||||||
| 1990 | 53.42 | 51.89 | 55.45 | 58.57 | 61.10 | 63.97 | 70.81 | 69.00 | 69.63 | 62.61 | 55.97 | 49.16 | 60.13 | |||||||||||||
| 1991 | 54.10 | 58.68 | 54.23 | 56.13 | 58.71 | 64.37 | 70.52 | 68.16 | 73.03 | 67.81 | 57.07 | 54.03 | 61.40 | |||||||||||||
| 1992 | 54.52 | 58.48 | 59.74 | 60.90 | 67.13 | 66.47 | 69.74 | 72.03 | 69.83 | 65.77 | 56.63 | 52.03 | 62.77 | |||||||||||||
| 1993 | 51.16 | 55.64 | 56.45 | 56.77 | 61.65 | 65.63 | 69.39 | 69.61 | 67.53 | 65.84 | 58.03 | 54.52 | 61.02 | |||||||||||||
| 1994 | 56.58 | 52.46 | 56.74 | 56.80 | 61.87 | 63.37 | 66.65 | 70.84 | 68.27 | 63.42 | 52.17 | 51.55 | 60.06 | |||||||||||||
| 1995 | 55.48 | 56.61 | 55.71 | 56.40 | 60.03 | 62.93 | 68.26 | 68.84 | 67.23 | 64.87 | 57.10 | 56.58 | 60.84 | |||||||||||||
| 1996 | 53.13 | 55.45 | 56.55 | 58.50 | 58.97 | 64.10 | 65.90 | 67.16 | 66.63 | 61.13 | 56.90 | 54.71 | 59.93 | |||||||||||||
| 1997 | 54.13 | 55.36 | 54.39 | 56.03 | 63.71 | 64.60 | 69.19 | 68.97 | 69.00 | 61.81 | 58.63 | 55.61 | 60.95 | |||||||||||||
| 1998 | 55.23 | 54.68 | 55.03 | 55.57 | 58.13 | 61.80 | 65.03 | 68.19 | 67.30 | 62.45 | 55.03 | 51.26 | 59.14 | |||||||||||||
| 1999 | 52.39 | 51.46 | 51.58 | 57.03 | 58.16 | 62.40 | 63.03 | 66.65 | 67.90 | 66.94 | m | 58.23 | 54.90 | 58.52 | ||||||||||||
| 2000 | 54.61 | 57.17 | 54.35 | 59.50 | 59.26 | 61.67 | 62.77 | 62.61 | 62.77 | 60.71 | 57.57 | 61.97 | 59.58 | |||||||||||||
| 2001 | 64.81 | 53.25 | 55.94 | 53.80 | 60.94 | 63.03 | 65.58 | 65.48 | 66.30 | 64.29 | 56.70 | 53.39 | 60.29 | |||||||||||||
| 2002 | 51.35 | 55.15 | a | 52.81 | 55.03 | a | 57.65 | 62.10 | 67.30 | a | 68.40 | a | 66.53 | 60.87 | 59.97 | 55.81 | 59.41 | |||||||||
| 2003 | 56.84 | 55.21 | 56.00 | 54.63 | 61.23 | 65.70 | 68.23 | 68.58 | 66.37 | 65.42 | 55.70 | 54.71 | 60.72 | |||||||||||||
| 2004 | 53.26 | 54.86 | 56.94 | 60.00 | 61.13 | 62.70 | 66.90 | ----- | z | 66.13 | 61.45 | 57.63 | 55.68 | 59.70 | ||||||||||||
| 2005 | 54.29 | 59.21 | 59.68 | 55.90 | 60.61 | 61.87 | 66.45 | 66.35 | 64.63 | 60.26 | 56.73 | 55.61 | 60.13 | |||||||||||||
| 2006 | 54.90 | 56.18 | 52.48 | 55.63 | 59.94 | 62.43 | 65.90 | 64.52 | 64.97 | 63.35 | 55.43 | 56.42 | 59.35 | |||||||||||||
| 2007 | 51.42 | 51.86 | 55.77 | 55.67 | 59.13 | 60.93 | 65.26 | 67.00 | 64.10 | 60.71 | 58.23 | 51.52 | 58.47 | |||||||||||||
| 2008 | 51.10 | 52.69 | 51.87 | 54.30 | 59.35 | 60.67 | 64.77 | 66.97 | 65.30 | 62.23 | 58.93 | 51.65 | 58.32 | |||||||||||||
| 2009 | 55.90 | 54.18 | 53.10 | 56.07 | 58.90 | 63.27 | 67.16 | 67.10 | 68.73 | 63.58 | 56.87 | 51.74 | 59.72 | |||||||||||||
| 2010 | 55.84 | 55.79 | 55.42 | 54.73 | 57.97 | 62.17 | 65.39 | 66.48 | 65.93 | 63.10 | 53.80 | 53.90 | 59.21 | |||||||||||||
| 2011 | 55.94 | 52.07 | 52.53 | a | 53.93 | 57.32 | 62.80 | 65.87 | 68.90 | 67.87 | 63.97 | 55.00 | 53.32 | 59.13 | ||||||||||||
| 2012 | 53.06 | 53.03 | 51.90 | 56.07 | 59.19 | 62.23 | 66.00 | 66.35 | 64.37 | 61.06 | 58.30 | 52.03 | 58.63 | |||||||||||||
| 2013 | 52.26 | 53.21 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 52.74 | |||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 54.03 | 55.01 | 55.58 | 57.27 | 60.90 | 64.25 | 67.47 | 68.42 | 67.73 | 63.41 | 57.09 | 54.01 | 60.46 | |||||||||||||
| S.D. | 2.87 | 2.41 | 2.50 | 2.08 | 2.05 | 1.90 | 1.86 | 1.83 | 2.06 | 1.98 | 1.88 | 2.45 | 1.16 | |||||||||||||
| SKEW | 1.13 | 0.05 | 0.00 | 0.34 | 0.62 | 0.05 | -0.38 | -0.67 | 0.21 | 0.27 | -0.50 | 0.41 | -0.02 | |||||||||||||
| MAX | 64.81 | 59.21 | 60.03 | 61.90 | 67.13 | 67.70 | 70.81 | 72.03 | 73.03 | 67.81 | 59.97 | 61.97 | 62.77 | |||||||||||||
| MIN | 47.47 | 49.82 | 50.10 | 53.80 | 57.32 | 60.67 | 62.77 | 62.61 | 62.77 | 60.26 | 52.17 | 49.16 | 58.32 | |||||||||||||
| NO YRS | 48 | 48 | 46 | 45 | 45 | 47 | 46 | 46 | 46 | 44 | 48 | 49 | 37 | |||||||||||||