| Period during year | ||
Year | Jan-Mar | Apr-Sept | Oct-Dec |
2005 | 37 | 594 | 153 |
2006 | 50 | 498 | 56 |
2007 | 135 | 356 | 127 |
2008 | 41 | 362 | 187 |
30-yr average | 70 | 442 | 91 |