| Year | Normal Rain | Actual Rainfall | Difference |
| 1998 | 67.50 | 60.68 | (-) 06.82 |
| 1999 | 67.50 | 62.30 | (-) 05.20 |
| 2000 | 67.50 | 38.60 | (-)28.40 |
| 2001 | 67.50 | 59.62 | (-)07.88 |
| 2002 | 67.50 | 39.49 | (-)28.01 |
| 2003 | 67.50 | 75.19 | (+)07.69 |
| 2004 | 67.50 | 44.87 | (-)22.63 |
| 2005 | 67.50 | 67.16 | (-) 0.34 |
| 2006 | 67.50 | 40.39 | (-)26.66 |
| 2007 | 67.50 | 48.70 | (-)18.35 |
| 2008 | 67.50 | 78.80 | (+)11.75 |