| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1971 | ----- | z | ----- | z | ----- | z | ----- | z | 58.00 | t | 63.13 | 65.10 | 69.90 | 70.57 | 61.77 | 54.00 | 46.32 | 61.54 | ||||||||
| 1972 | 46.42 | 52.48 | 54.97 | a | 55.80 | 62.42 | 67.03 | 72.26 | 71.35 | 69.73 | 63.94 | 55.30 | 45.87 | 59.80 | ||||||||||||
| 1973 | 47.43 | c | 57.61 | 54.48 | 61.23 | 63.35 | 67.43 | 68.81 | 68.45 | 71.50 | 62.84 | 51.36 | b | 51.58 | 60.51 | |||||||||||
| 1974 | 47.10 | 51.18 | 55.39 | 58.53 | 61.87 | 65.33 | 70.45 | 70.77 | 73.03 | 67.03 | 56.77 | 50.94 | 60.70 | |||||||||||||
| 1975 | 50.58 | 51.43 | 54.87 | 55.80 | 64.06 | 66.00 | a | 70.13 | 69.19 | 72.13 | 60.07 | b | 53.60 | 51.37 | a | 59.94 | ||||||||||
| 1976 | 51.29 | 50.79 | 54.48 | 58.07 | 64.19 | 66.30 | c | 71.90 | 69.81 | 73.17 | 66.65 | 59.77 | 52.29 | 61.56 | ||||||||||||
| 1977 | 53.29 | 57.86 | 54.84 | 61.50 | 62.13 | 67.70 | 70.65 | 72.10 | 67.83 | 65.81 | 53.90 | 50.81 | 61.53 | |||||||||||||
| 1978 | 50.58 | 52.36 | 56.94 | 55.47 | 62.13 | 66.73 | 67.84 | 67.90 | 65.93 | 63.42 | 49.97 | 44.32 | 58.63 | |||||||||||||
| 1979 | 43.45 | 47.96 | 54.55 | 56.77 | 61.74 | 65.47 | 69.68 | 69.48 | 70.73 | 62.00 | 53.63 | 53.36 | c | 59.07 | ||||||||||||
| 1980 | 48.13 | 54.10 | 52.90 | 57.90 | 60.97 | 63.80 | 67.97 | 65.52 | 66.13 | 63.74 | 55.53 | 52.84 | 59.13 | |||||||||||||
| 1981 | 55.39 | 54.14 | 54.87 | 57.80 | 61.55 | 65.63 | 67.16 | 67.03 | 66.57 | 59.45 | 53.27 | 51.03 | 59.49 | |||||||||||||
| 1982 | 45.81 | 50.00 | 51.74 | 54.73 | 60.71 | 62.40 | 66.03 | 66.94 | 67.57 | 63.58 | 52.90 | 50.71 | 57.76 | |||||||||||||
| 1983 | 53.48 | 54.25 | 57.26 | 61.17 | 63.97 | 66.53 | 69.74 | 70.90 | 70.20 | 63.32 | 54.27 | 48.16 | 61.10 | |||||||||||||
| 1984 | 52.97 | 55.38 | 57.77 | 57.63 | 62.32 | 63.50 | 67.23 | 70.52 | 69.57 | 59.90 | 53.07 | 48.06 | 59.83 | |||||||||||||
| 1985 | 52.48 | 51.21 | 52.52 | 57.73 | 63.42 | 67.67 | 68.19 | 68.23 | 67.70 | 61.32 | 47.90 | 51.81 | 59.18 | |||||||||||||
| 1986 | 54.35 | 53.54 | 60.74 | 58.03 | 62.32 | 67.30 | 68.00 | 66.35 | 64.77 | 61.42 | 55.90 | 51.45 | 60.35 | |||||||||||||
| 1987 | 51.97 | 55.07 | 57.97 | 62.03 | 64.97 | 66.37 | 66.74 | 68.84 | 67.03 | 66.48 | 56.43 | 47.94 | 60.99 | |||||||||||||
| 1988 | 49.32 | 56.17 | 56.65 | 59.13 | 62.71 | 65.93 | 69.65 | 68.06 | 68.67 | 63.97 | 53.53 | 50.94 | 60.39 | |||||||||||||
| 1989 | 50.39 | 47.43 | 53.94 | 64.10 | 64.13 | 68.73 | 69.65 | 70.52 | 71.33 | 62.71 | 56.27 | 52.68 | 60.99 | |||||||||||||
| 1990 | 51.19 | 51.82 | 57.29 | 60.80 | 62.87 | a | 66.67 | 69.39 | 70.32 | 71.60 | 61.94 | 54.57 | 44.87 | 60.28 | ||||||||||||
| 1991 | 51.16 | 58.39 | 54.52 | 57.40 | 60.26 | 65.00 | 70.32 | 70.16 | 76.27 | 68.09 | i | 56.77 | 51.00 | 61.02 | ||||||||||||
| 1992 | 53.13 | 60.21 | 61.13 | 63.67 | 70.32 | 69.80 | j | 71.94 | 73.00 | 69.70 | 64.52 | 54.33 | 48.29 | 62.75 | ||||||||||||
| 1993 | 47.94 | 54.14 | 58.26 | 59.63 | 66.00 | 68.33 | 70.65 | 72.35 | 68.37 | 63.87 | 52.93 | 51.52 | 61.17 | |||||||||||||
| 1994 | 53.84 | 51.25 | 59.10 | 60.60 | 65.35 | 66.87 | 70.65 | 74.77 | 72.20 | 63.29 | 50.30 | 49.90 | 61.51 | |||||||||||||
| 1995 | 52.52 | 57.29 | 57.19 | 60.43 | 64.72 | m | 69.65 | j | 72.81 | 72.86 | q | 71.72 | l | 64.00 | 57.73 | 55.15 | r | 60.28 | ||||||||
| 1996 | 51.19 | 54.14 | 60.19 | 58.18 | s | 63.50 | y | 68.86 | i | 71.32 | 73.33 | p | 70.80 | 63.00 | 56.47 | 52.10 | 59.90 | |||||||||
| 1997 | 51.35 | 54.57 | 55.52 | 60.73 | 69.41 | i | ----- | z | 73.55 | k | 73.95 | l | 73.29 | i | 61.55 | 57.28 | l | 52.95 | k | 56.74 | ||||||
| 1998 | 51.86 | j | 53.86 | 57.86 | i | 60.27 | 63.29 | n | 67.53 | 69.44 | m | 74.91 | t | 70.22 | u | 64.00 | 54.23 | 49.30 | a | 58.20 | ||||||
| 1999 | 50.84 | 52.00 | n | 53.81 | 60.14 | p | 63.20 | p | 66.73 | 67.61 | 71.48 | j | 70.15 | j | 62.88 | f | 57.34 | a | 52.67 | m | 59.27 | |||||
| 2000 | 49.73 | i | 53.83 | 54.63 | a | 62.62 | i | 62.65 | 68.73 | 69.75 | o | 70.00 | n | 71.10 | j | 63.52 | 54.00 | q | 52.81 | 59.36 | ||||||
| 2001 | 53.06 | 52.54 | 56.06 | 56.70 | 67.00 | i | 65.70 | j | 69.00 | 68.68 | i | 69.44 | l | 61.29 | 56.87 | 49.81 | 56.92 | |||||||||
| 2002 | 49.54 | g | 54.36 | f | 54.10 | a | 59.19 | c | 61.70 | d | 66.32 | k | 71.33 | g | 72.91 | h | 69.11 | k | 61.04 | f | 48.62 | a | 53.41 | d | 55.40 | |
| 2003 | 55.87 | h | 54.17 | d | 57.86 | j | 57.78 | g | 64.23 | e | 68.91 | g | 72.45 | i | 73.00 | j | 70.68 | e | 64.00 | k | 51.96 | e | 50.56 | d | 58.32 | |
| 2004 | 51.11 | c | 54.48 | b | 58.83 | g | 65.92 | d | 64.91 | i | 68.63 | k | 74.42 | l | 73.28 | f | 69.60 | j | 61.42 | 54.53 | 52.20 | f | 57.49 | |||
| 2005 | 51.71 | g | 56.05 | g | 59.48 | j | 59.32 | h | 66.31 | e | 67.50 | l | 71.39 | h | 65.84 | 63.20 | 58.50 | k | 52.20 | 48.90 | 59.29 | |||||
| 2006 | 50.26 | 51.04 | 50.61 | 56.80 | j | ----- | z | 66.47 | ----- | z | 62.84 | 64.33 | 59.26 | 51.30 | 48.87 | 56.11 | ||||||||||
| 2007 | 46.52 | 49.00 | 53.67 | a | 56.52 | a | 58.81 | d | 62.80 | e | 67.61 | c | 67.56 | f | 65.07 | 59.06 | 52.13 | 51.74 | 56.63 | |||||||
| 2008 | 44.48 | 49.14 | g | 49.68 | 52.81 | c | 59.77 | 59.63 | 64.48 | 64.77 | 63.70 | 59.58 | 54.97 | 45.10 | 56.27 | |||||||||||
| 2009 | 49.87 | 51.04 | 49.52 | 54.03 | 58.26 | 62.10 | 64.00 | 66.03 | 66.57 | 58.71 | 53.20 | 45.74 | 56.59 | |||||||||||||
| 2010 | 51.52 | 52.36 | 52.84 | 53.60 | 56.32 | 61.33 | 62.29 | 62.65 | 64.43 | 59.58 | 49.47 | 48.71 | 56.26 | |||||||||||||
| 2011 | 49.03 | 47.14 | 50.42 | 51.77 | 56.67 | d | 63.33 | 65.97 | 67.10 | 67.20 | 60.55 | 51.33 | 47.42 | 56.49 | ||||||||||||
| 2012 | 49.47 | a | 49.72 | 49.32 | 55.41 | a | 59.10 | 62.00 | 64.19 | 65.26 | 62.93 | 59.45 | 53.63 | 45.52 | 56.33 | |||||||||||
| 2013 | 46.16 | 48.57 | 52.45 | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | ----- | z | 49.06 | ||||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 50.25 | 52.96 | 54.93 | 58.37 | 62.35 | 65.47 | 68.51 | 68.61 | 68.57 | 62.38 | 53.81 | 49.68 | 59.58 | |||||||||||||
| S.D. | 2.87 | 3.08 | 3.00 | 3.23 | 2.81 | 2.32 | 2.59 | 2.89 | 3.25 | 2.24 | 2.59 | 2.60 | 1.70 | |||||||||||||
| SKEW | -0.52 | 0.16 | 0.06 | 0.14 | 0.15 | -0.71 | -0.47 | -0.16 | 0.10 | 0.18 | -0.18 | -0.54 | -0.84 | |||||||||||||
| MAX | 55.39 | 60.21 | 61.13 | 65.92 | 70.32 | 68.73 | 72.81 | 74.77 | 76.27 | 67.03 | 59.77 | 53.41 | 61.56 | |||||||||||||
| MIN | 43.45 | 47.14 | 49.32 | 51.77 | 56.32 | 59.63 | 62.29 | 62.65 | 62.93 | 58.71 | 47.90 | 44.32 | 56.26 | |||||||||||||
| NO YRS | 37 | 38 | 38 | 35 | 33 | 33 | 34 | 31 | 34 | 37 | 40 | 38 | 25 | |||||||||||||