| Year | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | Average |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| January | 0.64 | 3.40 | 2.68 | 0.61 | 0.67 | 4.49 | 3.14 | 2.53 | 2.65 | 0.22 | 1.32 | 0.59 | 1.91 |
| February | 1.87 | 2.85 | 1.31 | 1.09 | 0.33 | 1.65 | 0.15 | 1.74 | 3.44 | 2.18 | 1.46 | 2.80 | 1.74 |
| March | 1.71 | 1.55 | 1.60 | 1.84 | 2.84 | 0.71 | 2.17 | 4.66 | 1.56 | 4.50 | 2.31 | 1.37 | 2.24 |
| April | 1.61 | 3.60 | 4.32 | 3.75 | 1.78 | 2.09 | 4.34 | 2.46 | 2.76 | 6.01 | 2.84 | 5.85 | 3.76 |
| May | 4.42 | 5.06 | 5.46 | 3.20 | 5.56 | 0.88 | 2.22 | 1.75 | 3.00 | 4.02 | 6.46 | 3.22 | 3.77 |
| June | 4.88 | 3.21 | 4.24 | 4.50 | 3.56 | 1.33 | 1.82 | 4.50 | 5.02 | 4.62 | 7.40 | 5.98 | 4.26 |
| July | 4.47 | 1.32 | 4.09 | 6.04 | 2.30 | 1.64 | 4.02 | 2.46 | 5.52 | 5.16 | 5.64 | 2.05 | 3.73 |
| August | 2.02 | 3.84 | 5.40 | 4.43 | 3.77 | 2.68 | 2.88 | 1.30 | 2.27 | 6.23 | 3.02 | 0.51 | 3.20 |
| September | 1.95 | 2.37 | 0.39 | 2.63 | 0.98 | 2.38 | 2.34 | 0.80 | 10.32 | 2.65 | 4.87 | 2.23 | 2.83 |
| October | 1.80 | 4.95 | 1.65 | 1.56 | 5.17 | 1.24 | 2.19 | 2.30 | 2.21 | 8.08 | 2.01 | 0.47 | 2.80 |
| November | 2.10 | 2.54 | 0.62 | 3.54 | 4.54 | 2.64 | 3.85 | 1.62 | 0.97 | 3.42 | 1.72 | 4.14 | 2.64 |
| December | 1.18 | 1.45 | 1.95 | 1.07 | 1.23 | 0.95 | 2.16 | 4.07 | 2.88 | 3.30 | 3.19 | 3.01 | 2.20 |
| TOTAL | 28.65 | 36.14 | 33.71 | 34.26 | 32.73 | 22.40 | 35.13 | 30.19 | 42.60 | 50.39 | 42.24 | 32.67 | 35.08 |
Last updated 1-10-2012