| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1979 | 64.23 | 67.36 | 70.84 | 79.90 | a | 79.74 | 88.37 | 89.27 | a | 87.45 | b | 94.15 | d | 80.03 | 74.40 | 75.28 | b | 79.25 | ||||||||
| 1980 | 68.23 | 73.14 | 71.84 | 78.52 | a | 75.03 | b | 84.79 | a | 91.87 | 89.50 | a | 85.66 | a | 84.68 | 77.48 | a | 75.45 | 79.68 | |||||||
| 1981 | 71.57 | a | 76.04 | c | 71.24 | b | 77.66 | a | 81.87 | 91.57 | 91.58 | 93.58 | 88.24 | a | 80.57 | a | 75.79 | a | 70.94 | 80.89 | ||||||
| 1982 | 66.90 | 70.71 | 69.45 | 74.47 | 75.61 | 76.77 | 88.61 | 89.87 | 86.80 | 83.81 | 71.73 | 68.39 | 76.93 | |||||||||||||
| 1983 | 69.81 | 69.29 | 69.81 | 71.40 | 78.55 | 78.20 | 87.48 | 91.94 | 89.37 | 82.45 | 71.80 | 66.94 | 77.25 | |||||||||||||
| 1984 | 72.90 | a | ----- | z | 76.81 | 76.70 | 87.00 | 82.87 | 92.35 | 89.68 | 94.73 | 79.58 | 72.20 | 65.65 | 80.95 | |||||||||||
| 1985 | 67.71 | 70.57 | 69.23 | 78.13 | 76.16 | 85.60 | 91.97 | 89.65 | 83.87 | 82.23 | 70.63 | 73.84 | 78.30 | |||||||||||||
| 1986 | 74.68 | 69.82 | 73.26 | 77.83 | 79.26 | 83.50 | 86.23 | 90.52 | 80.10 | 81.87 | 79.27 | 72.19 | 79.04 | |||||||||||||
| 1987 | 68.68 | 70.71 | 71.68 | 82.40 | 79.00 | 82.00 | 83.00 | 86.39 | 88.07 | 82.65 | 74.27 | 65.61 | 77.87 | |||||||||||||
| 1988 | 69.81 | 75.86 | 78.61 | 77.70 | ----- | z | 82.60 | 89.13 | 85.58 | 85.40 | 81.97 | 74.17 | 69.71 | 79.14 | ||||||||||||
| 1989 | 69.48 | 68.36 | 74.77 | 81.47 | 78.00 | 80.73 | 88.87 | 85.77 | 88.20 | 79.74 | 79.17 | 75.94 | 79.21 | |||||||||||||
| 1990 | 72.13 | 68.46 | 72.39 | 76.93 | 79.03 | 87.97 | 92.03 | 88.19 | 89.07 | 85.97 | 79.13 | 70.19 | 80.12 | |||||||||||||
| 1991 | 69.87 | 76.89 | 67.90 | 77.13 | 77.03 | ----- | z | ----- | z | 87.13 | 87.23 | 85.61 | 78.97 | 70.23 | 77.80 | |||||||||||
| 1992 | 72.13 | 72.00 | 68.84 | 81.80 | 80.26 | 83.30 | 87.87 | 92.68 | 90.43 | ----- | z | 77.47 | 66.52 | 79.39 | ||||||||||||
| 1993 | 65.55 | 67.07 | 75.97 | 81.13 | 82.19 | 85.43 | 83.84 | 86.87 | 86.60 | 82.94 | 75.53 | 71.68 | 78.73 | |||||||||||||
| 1994 | ----- | z | 69.29 | 75.35 | 74.67 | 75.71 | 87.90 | 86.10 | 93.06 | 89.30 | 80.84 | 71.27 | 70.39 | 79.44 | ||||||||||||
| 1995 | 65.29 | 75.86 | 72.03 | 77.13 | 74.45 | 80.93 | 89.32 | 91.39 | 90.03 | 82.42 | ----- | z | 70.26 | 79.01 | ||||||||||||
| 1996 | ----- | z | 70.17 | 73.84 | 82.00 | 81.58 | 85.50 | 89.94 | 90.77 | 86.37 | 79.74 | 76.83 | 73.13 | 80.90 | ||||||||||||
| 1997 | 68.23 | 73.11 | 79.29 | ----- | z | 85.26 | 82.30 | 85.65 | 90.97 | 93.00 | 83.55 | 78.13 | 70.45 | 80.90 | ||||||||||||
| 1998 | 69.19 | 66.57 | 73.32 | 73.93 | 74.03 | 80.60 | 89.84 | 93.35 | 83.23 | 81.06 | 74.07 | a | 71.52 | 77.56 | ||||||||||||
| 1999 | 71.95 | j | 71.07 | 69.48 | 72.53 | 76.81 | 81.30 | 87.77 | 89.10 | 84.73 | 90.50 | a | 75.63 | 75.35 | 79.48 | |||||||||||
| 2000 | 71.32 | 70.10 | 72.19 | 81.20 | 82.94 | ----- | z | 88.58 | 91.29 | 89.37 | 78.68 | i | 74.53 | 76.14 | q | 80.17 | ||||||||||
| 2001 | 69.13 | a | 66.86 | 70.05 | i | 76.10 | j | 81.32 | 86.53 | 86.56 | o | 87.85 | k | 88.44 | l | 83.28 | m | 73.50 | p | ----- | z | 75.96 | ||||
| 2002 | 70.26 | 77.07 | 73.26 | 73.40 | j | ----- | z | ----- | z | 90.20 | k | 87.32 | i | 92.88 | n | 76.35 | n | 77.50 | r | 71.92 | s | 73.53 | ||||
| 2003 | 80.19 | j | 71.79 | i | 76.52 | j | 75.20 | e | 81.55 | k | 80.69 | n | 91.28 | m | 94.39 | h | 89.80 | j | 91.28 | m | 82.40 | y | 70.40 | z | 75.20 | |
| 2004 | 75.50 | w | 67.12 | m | 80.54 | g | 78.77 | 85.32 | c | 83.20 | 88.68 | 87.94 | 92.61 | l | 80.67 | s | 74.69 | q | 74.75 | s | 84.78 | |||||
| 2005 | 68.50 | m | 71.64 | q | 75.42 | e | 78.90 | j | 82.45 | k | 81.95 | k | 90.70 | k | 91.95 | k | 86.88 | m | 84.50 | k | 81.00 | v | 74.32 | l | 75.42 | |
| 2006 | 73.70 | h | 76.00 | n | 65.71 | n | 76.11 | k | 81.25 | k | 89.15 | q | 97.09 | t | 90.62 | o | 91.78 | u | 75.33 | z | ----- | z | 70.33 | z | 9999.00 | |
| 2007 | 68.36 | q | 72.90 | r | 83.00 | q | 80.60 | y | 84.50 | w | 88.09 | s | 92.62 | o | 95.31 | o | 96.33 | x | 90.20 | u | 84.83 | x | ----- | z | 9999.00 | |
| 2008 | 71.50 | w | 77.50 | z | 85.80 | z | 101.00 | z | 93.50 | z | ----- | z | 93.00 | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| 2009 | ----- | z | 73.14 | g | 76.14 | i | 81.00 | h | 84.74 | h | 80.57 | p | 92.36 | q | 91.92 | r | 92.06 | m | ----- | z | ----- | z | 68.16 | 68.16 | ||
| 2010 | 71.39 | h | 71.20 | r | 75.65 | 73.13 | 77.50 | g | 81.91 | g | 85.54 | e | 87.47 | l | 88.74 | g | 79.00 | v | ----- | z | ----- | z | 78.11 | |||
| 2011 | 66.20 | p | 71.20 | r | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 9999.00 | |
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 69.38 | 71.15 | 72.90 | 77.57 | 79.40 | 83.73 | 88.50 | 89.68 | 87.91 | 82.61 | 75.36 | 70.81 | 78.74 | |||||||||||||
| S.D. | 2.60 | 3.31 | 3.04 | 3.17 | 3.62 | 3.49 | 2.59 | 2.44 | 3.50 | 2.64 | 2.80 | 3.15 | 1.20 | |||||||||||||
| SKEW | -0.11 | 0.49 | 0.34 | -0.18 | 0.41 | 0.20 | -0.33 | -0.08 | 0.02 | 1.34 | -0.11 | 0.02 | 0.04 | |||||||||||||
| MAX | 74.68 | 77.07 | 79.29 | 82.40 | 87.00 | 91.57 | 92.35 | 93.58 | 94.73 | 90.50 | 79.27 | 75.94 | 80.89 | |||||||||||||
| MIN | 64.23 | 66.57 | 67.90 | 71.40 | 74.03 | 76.77 | 83.00 | 85.58 | 80.10 | 79.58 | 70.63 | 65.61 | 76.93 | |||||||||||||
| NO YRS | 21 | 23 | 25 | 24 | 23 | 22 | 23 | 23 | 22 | 20 | 21 | 22 | 12 | |||||||||||||