| YEAR(S) | JAN | FEB | MAR | APR | MAY | JUN | JUL | AUG | SEP | OCT | NOV | DEC | ANN | |||||||||||||
| 1990 | 0.00 | z | 0.00 | z | 0.27 | 1.56 | 1.34 | 0.47 | 0.31 | 1.07 | 0.02 | 0.52 | b | 0.41 | 0.09 | q | 5.97 | |||||||||
| 1991 | 0.12 | f | 0.14 | b | 0.41 | f | 0.67 | b | 1.95 | a | 0.25 | 0.20 | 0.05 | 0.19 | 1.06 | a | 1.27 | h | 0.34 | d | 4.85 | |||||
| 1992 | 0.20 | e | 0.68 | d | 0.20 | 0.33 | a | 0.20 | 0.94 | a | 0.52 | a | 0.00 | 0.04 | 0.77 | b | 1.61 | i | 0.54 | 4.42 | ||||||
| 1993 | 1.01 | h | 0.41 | f | 3.15 | e | 2.61 | d | 0.62 | a | 1.97 | b | 0.99 | c | 0.77 | c | 0.00 | 0.00 | z | 0.99 | d | 0.57 | a | 11.67 | ||
| 1994 | 0.94 | f | 0.46 | b | 0.11 | 0.00 | z | 1.25 | b | 0.15 | a | 0.00 | 0.00 | 0.02 | 1.29 | a | 1.96 | f | 0.69 | e | 3.97 | |||||
| 1995 | 1.49 | d | 0.24 | b | 0.97 | b | 0.86 | c | 2.02 | b | 0.95 | a | 0.60 | c | 0.22 | 0.00 | 0.46 | a | 1.57 | e | 1.62 | h | 9.38 | |||
| 1996 | 0.64 | a | 0.89 | c | 1.04 | 0.61 | a | 1.89 | b | 0.11 | a | 0.05 | a | 0.04 | 0.39 | a | 0.56 | a | 1.28 | c | 1.77 | j | 7.50 | |||
| 1997 | 2.12 | d | 0.00 | c | 0.07 | a | 0.31 | c | 0.80 | c | 0.44 | b | 0.65 | b | 0.13 | a | 0.86 | b | 0.07 | 0.79 | b | 0.65 | b | 6.89 | ||
| 1998 | 2.21 | g | 1.19 | g | 1.02 | d | 1.40 | a | 3.50 | h | 0.55 | b | 0.71 | e | 0.02 | 1.04 | b | 0.00 | 0.47 | g | 0.73 | e | 5.47 | |||
| 1999 | 1.12 | c | 0.89 | d | 0.43 | a | 0.60 | a | 0.47 | a | 0.40 | 0.04 | 0.33 | 0.00 | 0.24 | a | 0.05 | d | 0.00 | z | 4.57 | |||||
| 2000 | 0.82 | k | 0.95 | d | 1.20 | b | 0.89 | b | 0.48 | a | 0.32 | a | 0.00 | 0.00 | 0.38 | c | 2.31 | 1.02 | c | 0.12 | 7.67 | |||||
| 2001 | 1.33 | x | 0.09 | 0.63 | 1.54 | b | 0.20 | 0.05 | a | 0.59 | a | 0.00 | 0.00 | 0.48 | 0.83 | d | 0.75 | b | 5.16 | |||||||
| 2002 | 0.84 | e | 0.08 | 0.48 | c | 0.86 | a | 0.00 | 0.01 | 0.10 | b | 0.02 | b | 0.34 | 0.04 | 0.11 | b | 1.72 | g | 2.88 | ||||||
| 2003 | 1.61 | e | 0.90 | f | 1.06 | b | 0.61 | a | 1.06 | i | 0.06 | 0.23 | 0.49 | b | 0.05 | 0.00 | 0.28 | d | 1.86 | h | 4.39 | |||||
| 2004 | 1.13 | f | 0.82 | 0.02 | 0.35 | 1.72 | d | 0.36 | a | 0.59 | b | 0.39 | b | 0.42 | b | 1.18 | d | 0.97 | b | 0.39 | 7.21 | |||||
| 2005 | 0.08 | d | 0.18 | b | 1.26 | d | 0.77 | d | 2.17 | i | 1.17 | d | 0.10 | b | 0.00 | 0.00 | a | 0.98 | b | 1.44 | h | 1.72 | h | 4.54 | ||
| 2006 | 1.22 | h | 0.26 | 1.08 | h | 1.32 | d | 0.72 | g | 0.56 | d | 0.26 | e | 0.04 | 0.59 | 0.33 | c | 0.60 | j | 0.72 | f | 3.36 | ||||
| 2007 | 0.15 | b | 0.74 | d | 0.09 | b | 0.83 | e | 0.16 | 1.16 | d | 0.00 | 0.20 | b | 1.00 | c | 0.59 | b | 1.00 | d | 0.90 | f | 5.92 | |||
| 2008 | 0.25 | g | 0.18 | e | 0.47 | b | 0.18 | a | 0.42 | c | 1.13 | b | 0.00 | 0.01 | 0.87 | b | 0.30 | b | 0.87 | d | 0.52 | i | 4.43 | |||
| 2009 | 0.64 | c | 0.46 | 0.73 | 0.35 | 0.88 | 2.82 | 0.00 | 0.50 | 0.00 | 0.87 | 0.88 | 1.07 | 9.20 | ||||||||||||
| 2010 | 1.65 | 1.59 | 0.82 | 0.37 | 0.71 | 2.00 | 0.00 | 0.53 | 0.00 | 0.83 | 0.96 | 2.29 | 11.75 | |||||||||||||
| 2011 | 1.46 | 0.61 | 2.72 | 1.08 | 1.15 | 0.61 | 0.18 | 0.15 | 0.31 | 1.27 | 0.50 | 0.61 | 10.65 | |||||||||||||
| 2012 | 1.31 | a | 0.16 | a | 0.99 | a | 1.07 | 0.77 | 0.32 | a | 0.00 | 0.00 | 0.06 | 0.77 | 0.62 | 0.54 | 6.61 | |||||||||
| 2013 | 0.50 | 0.31 | 0.02 | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.00 | z | 0.83 | ||||
| Period of Record Statistics | ||||||||||||||||||||||||||
| MEAN | 0.99 | 0.49 | 0.81 | 0.87 | 0.90 | 0.73 | 0.27 | 0.22 | 0.29 | 0.68 | 0.77 | 0.71 | 9.02 | |||||||||||||
| S.D. | 0.64 | 0.40 | 0.80 | 0.56 | 0.64 | 0.72 | 0.30 | 0.29 | 0.36 | 0.55 | 0.40 | 0.52 | 2.26 | |||||||||||||
| SKEW | 0.07 | 1.00 | 1.64 | 1.37 | 0.47 | 1.45 | 0.87 | 1.50 | 1.01 | 1.11 | -0.16 | 2.18 | 0.02 | |||||||||||||
| MAX | 2.12 | 1.59 | 3.15 | 2.61 | 2.02 | 2.82 | 0.99 | 1.07 | 1.04 | 2.31 | 1.57 | 2.29 | 11.75 | |||||||||||||
| MIN | 0.08 | 0.00 | 0.02 | 0.18 | 0.00 | 0.01 | 0.00 | 0.00 | 0.00 | 0.00 | 0.05 | 0.12 | 6.61 | |||||||||||||
| NO YRS | 14 | 20 | 22 | 22 | 19 | 23 | 23 | 23 | 23 | 22 | 17 | 13 | 5 | |||||||||||||