单位：十亿立方英尺
| 年 | 一月 | 二月 | 三月 | 四月 | 五月 | 六月 | 七月 | 八月 | 九月 | 十月 | 十一月 | 十二月 |
| 2001 | 2,677 | 2,309 | 2,247 | 1,807 | 1,522 | 1,444 | 1,598 | 1,669 | 1,494 | 1,649 | 1,701 | 2,120 |
| 2002 | 2,487 | 2,240 | 2,258 | 1,879 | 1,610 | 1,589 | 1,748 | 1,723 | 1,542 | 1,643 | 1,910 | 2,376 |
| 2003 | 2,701 | 2,500 | 2,198 | 1,744 | 1,515 | 1,368 | 1,600 | 1,652 | 1,429 | 1,553 | 1,754 | 2,264 |
| 2004 | 2,674 | 2,510 | 2,100 | 1,744 | 1,572 | 1,483 | 1,584 | 1,577 | 1,481 | 1,556 | 1,782 | 2,326 |
| 2005 | 2,561 | 2,243 | 2,205 | 1,725 | 1,522 | 1,534 | 1,686 | 1,695 | 1,422 | 1,428 | 1,663 | 2,326 |
| 2006 | 2,164 | 2,143 | 2,125 | 1,680 | 1,525 | 1,550 | 1,758 | 1,751 | 1,461 | 1,643 | 1,764 | 2,121 |
| 2007 | 2,475 | 2,566 | 2,129 | 1,810 | 1,558 | 1,555 | 1,659 | 1,896 | 1,590 | 1,627 | 1,834 | 2,398 |
| 2008 | 2,733 | 2,503 | 2,277 | 1,823 | 1,576 | 1,604 | 1,708 | 1,682 | 1,460 | 1,635 | 1,868 | 2,399 |
| 2009 | 2,721 | 2,325 | 2,164 | 1,736 | 1,499 | 1,523 | 1,653 | 1,731 | 1,570 | 1,662 | 1,771 | 2,484 |
| 2010 | 2,840 | 2,508 | 2,159 | 1,695 | 1,615 | 1,643 | 1,821 | 1,880 | 1,629 | 1,653 | 1,967 | 2,724 |
| 2011 | 2,877 | 2,451 | 2,212 | |||||||||
