|
| 1月 | 2月 | 3月 | 4月 | 5月 | 6月 |
| 2002 | 4.0916 | 3.9232 | 4.1807 | 4.2151 | 4.2515 | 4.2625 |
| 2003 | 4.4536 | 4.2151 | 4.5114 | 4.5174 | 4.4898 | 4.5685 |
| 2004 | 4.6131 | 4.5444 | 4.7449 | 4.7875 | 4.7908 | 4.8339 |
| 2005 | 4.9579 | 4.7131 | 4.9663 | 5.0265 | 5.0193 | 5.0421 |
| 2006 | 5.0937 | 4.8331 | 5.1405 | 5.1818 | 5.2051 | 5.2396 |
| 2007 | 5.3215 | 5.1985 | 5.3122 | 5.3936 | 5.3982 | 5.4072 |
| 2008 | 5.4621 | 5.2241 | 5.4790 | 5.4819 | 5.4702 | 5.4943 |
| 2009 | 5.2476 | 5.0291 | 5.3863 | 5.2771 | 5.3428 | 5.3033 |
|
| 7月 | 8月 | 9月 | 10月 | 11月 | 12月 |
| 2002 | 4.2750 | 4.3666 | 4.3906 | 4.3231 | 4.4118 | 4.4694 |
| 2003 | 4.5788 | 4.6112 | 4.6161 | 4.6299 | 4.6405 | 4.6161 |
| 2004 | 4.8315 | 4.8402 | 4.8744 | 4.8767 | 4.8888 | 4.8881 |
| 2005 | 5.0770 | 5.0789 | 5.0531 | 5.0676 | 5.0795 | 5.0490 |
| 2006 | 5.2601 | 5.2745 | 5.3003 | 5.2523 | 5.2559 | 5.2617 |
| 2007 | 5.4250 | 5.4407 | 5.4165 | 5.4179 | 5.4157 | 5.4385 |
| 2008 | 5.4604 | 5.5440 | 5.4613 | 5.4819 | 5.4289 | 5.4112 |
| 2009 | 5.3683 | 5.3882 | 5.4040 | 5.3808 | 5.3950 | 5.4798 |