| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Total | |
| 2010 | 0.69 | 1.13 | 0.06 | 1.88 | ||||||||||
| 2009 | 0.59 | 2.04 | 3.56 | 3.07 | 2.39 | 3.74 | 2.16 | 3.75 | 1.59 | 4.06 | 1.28 | 2.74 | 30.97 | |
| 2008 | 2.52 | 2.87 | 0.82 | 6.21 | 2.10 | 11.75 | 5.04 | 1.91 | 1.31 | 1.83 | 1.17 | 3.33 | 40.86 | |
| 2007 | 1.19 | 1.26 | 2.70 | 2.49 | 2.75 | 2.55 | 2.07 | 6.14 | 2.19 | 3.68 | 0.26 | 3.20 | 30.48 | |
| 2006 | 1.91 | 2.51 | ||||||||||||
| Most | 2.52 | 2.87 | 3.56 | 6.21 | 2.75 | 11.75 | 5.04 | 6.14 | 2.19 | 4.06 | 1.91 | 3.33 | 40.86 | |
| Least | 0.59 | 1.13 | 0.06 | 2.49 | 2.10 | 2.55 | 2.07 | 1.91 | 1.31 | 1.83 | 0.26 | 2.51 | 30.48 | |
| OSH Average | 1.35 | 1.09 | 2.18 | 2.87 | 2.96 | 3.66 | 3.58 | 4.15 | 3.47 | 2.20 | 2.51 | 1.55 | 31.57 | |
| 2-Mar-10 | ||||||||||||||